CHAPTER 5: THE TUTOR Onee-chan TEACHER

Ever since that day, Yurika’s erotic invasion knew no bounds. Every time she found a gap in the parents' supervision, she’d pepper him with kisses.

Yuu was happy to be the object of his sister’s affection, but he spent his days in a state of constant anxiety, worried they’d be caught. It was as if he had been completely enslaved by Yurika’s charm and "training."

And today, the sister’s fierce offensive began once more—

The moment Yuu woke up, he felt someone’s presence by his bed.

"Mmh... what...?"

"Yuu-kun, it’s morning~♡"

"Eh?"

Yuu opened his eyes to see Yurika’s smiling face in extreme close-up.

"Here you go, Yuu-kun~♡ Your 'Good Morning' kiss! Mwah!♡"

He felt a soft sensation on his cheek.

"Whoa! W-W-What was that for?!"

"It’s your fault for not waking up. I already gave you tons of kisses while you were asleep."

"Hey! Don't do that first thing in the morning!"

Taking advantage of the fact that Yuu was a heavy sleeper, Yurika had clearly been having her way with his cheeks. As Yuu sat up in bed, he was hit by an even more shocking sight.

Yurika was in her underwear.

"Whoa! P-Put some clothes on!"

"Eeeeh~? I’m in the middle of getting changed. I just came over to wake you up."

Saying that, Yurika spun around, putting her alluring body on full display. Her white panties were slightly buried in her plump, fleshy rear, while her large chest was emphasized by both deep cleavage and side-boob.

"Fufu~♡"

Yurika raised her arms above her head. With her armpits fully exposed, the line from her side-boob to her arms was perfectly highlighted.

"Guh...!"

(Ugh, she’s too sexy! Her butt and chest are amazing, but... her armpits are erotic too! D-Dammit... I used to think armpit fetishists were weird! I always thought breasts and butts were the only things that mattered! I'm sorry! To all the armpit fetishists in the world... I’m joining your ranks starting today!)

Thanks to Yurika, Yuu had acquired a brand-new fetish.

"Come on, it’s time for breakfast. Get up."

Yurika moved to pull back his covers, but Yuu frantically held them down.

"Wait! Hold on! I... I have a reason I can't get up right now!"

Because a certain part of him had "woken up," Yuu physically couldn't stand.

(I have a rager, I can't stand up! If I get up now, she’ll know I got turned on by her. I mean, she probably already knows, but still! It’s embarrassing...)

Ultimately, Yuu had no choice but to defend his blankets with his life.

"I’ll be down in a second, just... just go get changed, Onee-chan."

"Hmph. Well, I guess I have no choice."

Yurika acted as if she were letting go, but then—

"Gotcha! Mwah!♡"

She landed a high-speed kiss.

"Make sure you get out of bed, okay~?"

Slam!

Yuu sat there alone after the door closed. He wondered if his body would even survive the coming weeks if this was how every morning was going to start.

◆ ◇ ◆

When Yuu appeared in the dining room, his parents were already together, preparing breakfast. The sight was so heartwarming that Yuu sat down with a look of relief.

He glanced over at Yurika, who was talking to Mikiya as he peered into the fridge.

"Um, were we out of dressing?"

"Dad, the new bottle of dressing is in the cupboard."

"Oh, right, right."

Mikiya leaned over to look in the cupboard. Emiko was facing the stove. Yurika didn't miss the split second where both parents' gazes were diverted.

Mwah!♡

Targeting that window of two or three seconds, Yurika delivered a lightning-fast kiss to Yuu’s cheek.

(Wh-Wh-Wh-Whaaaaaat?! What is this erotic sister doing?! Right in front of our parents!?)

While Yuu sat there in a state of panic, Mikiya returned to the table.

"Found it. You really can't go wrong with sesame dressing."

"Really? I think Caesar is good too."

Despite how much her heart must have been pounding, Yurika conversed with her father as if nothing were wrong. This level of audacity made her the greatest warrior in the land... no, the greatest sister in Japan.

Yuu had no choice but to cover his face, pretending to rub his forehead to hide how red he was.

(Ugh! It’s too much for first thing in the morning. What is she going to do if we get caught? I knew she was a 'naughty' sister from the moment we met, but I feel like her combat power has been increasing lately.)

Watching Yurika through the gaps in his fingers, Yuu’s heart wouldn't stop racing.

(But... I love her too much to say anything...)

There were a mountain of things Yuu wanted to say to Yurika. But the sheer volume of his love for her allowed him to forgive everything.

"So, Yuu-kun, how is school?"

Mikiya’s sudden question snapped Yuu back to reality. "Ah, well... it’s okay."

"Is that so? Well, taking it easy is the best way to go."

Yuu genuinely liked his step-father, Mikiya. He was calm, kind, and gentle. Yuu was glad his mother had chosen him. Most importantly, it meant he got to be Yurika’s brother.

"So, do you have a girl you like?"

"Pffft!"

The sudden question nearly made Yuu spray his tea across the table. It was just casual small talk for Mikiya, but Yuu was terrified his father was asking about his relationship with Yurika.

"I-I don't! There isn't anyone I like!"

"I-Is that so? Well, no need to rush that, either."

"Yeah, exactly. I’m just taking it easy."

Emiko interjected into the awkward male conversation. "Dear, it’s still too early for Yuu."

Meanwhile, Yurika sat there silently, apologizing to Emiko in her head while masking her inner turmoil.

(S-S-S-Sorry! Mom! I’ve already done all sorts of things to Yuu-kun... He’s already started climbing the 'stairs to adulthood'...)

In reality, Yurika had been doing plenty of kissing and cuddling, and every night her head was filled with fantasies of forbidden sex. She even imagined "deviant" plays that she could never tell another living soul. Furthermore, she planned to finalize her "Reverse Hikaru Genji Plan" the moment Yuu graduated, putting those fantasies into practice. Specifically, the most erotic, immoral, and deviant versions of them.

Breakfast continued, and Mikiya eventually left for work. Emiko went to the front door to see him off, leaving the two of them alone in the dining room.

Naturally, the "erotic sister" wasn't about to miss this chance.

"Yuu-kun... Mwah!♡ Mwah!♡"

"W-We’re gonna get caught! Stop it!"

Yurika leaned over and peppered his cheek with kisses. Every time one landed, Yuu’s body would twitch, which only served to drive Yurika’s excitement higher.

(Ugh, Onee-chan... I want to kiss her too. I want to hold her soft body and just spoil her. I love her so much it’s driving me crazy.)

True to Yurika’s strategy, Yuu could no longer think of anything but his sister.

Though, to be fair—Yuu had never had eyes for any other girl. He had been a Yurika-simper from the start. His initial high affection level, combined with her daily aggressive skinship, had turned him into a "Slave of Love" who thought of nothing else, day or night.

"Yuu, you're going to be late if you keep dawdling."

Emiko returned from the entrance. The Yurika who had been clinging to him just a second ago was now sitting at a distance, sipping her tea as if nothing had happened. Her speed was god-tier.

"Good grief, Yuu. What are you doing?" Emiko asked, shrugging as she looked at Yuu, who was still holding his hand to his forehead to hide his face.

"Kuh! The twelve origins sleeping within me! The power of the Demon God King is about to go berserk!"

Yuu blurted out a line from an anime. It was a classic chuunibyou outburst.

"Just go to school already..." Emiko muttered, feeling a little worried that her son was being too influenced by his cartoons.

Whenever Yuu left the house, his "Have a Good Day" kiss from Yurika was a mandatory part of the routine. He had no idea how many times he was being kissed a day anymore.

Mwah!♡

Clack!

"Yuu, by the way, you have tests coming up soon. You’d better listen to what your sister tells you."

The moment the kiss landed, Emiko poked her head out from the dining room. Yuu froze, certain they’d been caught in the act.

"U-Um, th-this is—"

"There we go. You had some lint in your hair. You have to keep up your appearance, you know."

In that split second, Yurika had improvised. With a natural movement, she had acted as if she leaned in simply to pluck a stray thread from Yuu’s hair. It was a perfect performance that would look natural to anyone.

"There. Have a good day!"

"U-Um, yeah..."

Yuu opened the door to head out. Behind him, he could hear his sister and mother chatting naturally.

"Don't worry, I’ll take care of Yuu-kun’s test prep."

"That’s a big help."

Yurika could be a total klutz and crybaby at times, yet when it came to this sort of thing, her preparation and execution were flawless. Yuu realized he might never stand a chance against her.

◆ ◇ ◆

Yurika kept her promise to Emiko and began tutoring Yuu. Emiko had placed her absolute trust in the girl, yet Yurika spent every tutoring session messing with Yuu.

She was the picture of propriety in front of their parents, but the moment they were alone, she became a total flirt. Yuu had somehow managed to withstand her "erotic" offensive, holding his ground like an impregnable fortress.

However, that iron-clad defense was finally about to be breached. For today, Sensei Yurika was making her debut.

"Yuu-kun, it’s time for your lesson!"

Yurika appeared in Yuu’s room... dressed in a full "Teacher Cosplay." There was absolutely no reason for her to wear a suit just to tutor him at home, yet here she was in a professional woman’s business suit.

The suit was tailored to hug her curves, paired with a tight skirt that was dangerously short. Furthermore, her alluring legs were clad in thin, 20-denier black stockings.

※LEG-WEAR TRIVIA

Denier is a unit of measure for the thickness of fibers, commonly used to describe the thickness of tights and stockings. The lower the number, the thinner the material. Anything below 30 is generally referred to as "stockings."

"Wait, wait, wait! Why the suit?!"

Yuu was incredibly flustered. He never expected her to go full "naughty teacher" on him.

"Nnngh! Okay, Yuu-kun, let’s begin."

Sensei Yurika sat Yuu down in front of the low table and then slid into the spot right next to him.

Slide!

Her short skirt rode up, revealing the "Run Guard"—the transition point between the leg portion and the panty portion of the stockings. Through the thin black material, the beautiful, fleshy curve of her thighs was visible, creating an irresistible sexiness. The toes were slightly darker in color, a detail that was sure to tickle the heart of any connoisseur.

"Kuh... the stimulation..."

Since Yuu already had a preference for older women, Yurika’s teacher cosplay was a direct hit to his vitals.

(Gwah! This is the best! Her suit is too erotic! Dammit! I can't stop stealing glances!)

Yuu’s gaze drifted toward the top of Yurika’s thighs.

(Those stocking-clad legs! Every time her skirt rides up, I can't look away from that 'Run Guard' band! S-S-So this is the allure of tights?! To all the tights-fetishists in the world... I’m joining your ranks starting today!)

Thanks to Yurika, Yuu had acquired yet another brand-new fetish.

"Hey, Akashi-kun! Why are you dazing off? We have to study!"

"Huh? Y-Yes, ma'am!"

For some reason, Yurika had changed her persona. She was now acting like a strict, somewhat scary teacher. Even though her name was also Akashi, she was having a blast calling him "Akashi-kun." It seemed her "Sadistic Older Sister" mode was in full effect.

"We’ll start with math. Open your textbook."

"Yes, ma'am."

"This is a system of equations—"

As an education major, Yurika was actually a very good teacher. She was kind, thorough, and easy to understand—and she did it all while acting like a sexy teacher. It was the ultimate scenario.

However, Yuu couldn't focus because of the "Direct Hit" woman sitting right next to him.

(Onee-chan's lessons are actually really clear. But... I can't stop thinking about her sexy thigh rubbing against me! That skirt is too short!)

For a newly minted tights-connoisseur, it was a dream scenario. Not only was the "Run Guard" visible, but he was just inches away from seeing the diamond gusset or the center seam. There was no way Yuu could win against his sister’s temptations.

"Hey, Akashi-kun! Where are you looking?"

"Eh? S-Sorry!"

"You don't seem very focused on your studies, do you? Naughty boys need to be punished by their teacher!"

Caught up in the role, Yurika decided to dole out some punishment. Gone was her usual gentle, airy tone; she was using a strict, commanding voice that perfectly suited her costume.

"Here. Your punishment is a leg-lock."

Yurika extended her alluring, stocking-clad legs and entangled them around Yuu’s upper body. She used her legs to pull him down, eventually wrapping them around his neck.

"Eeeeh! Hey, wait, whoa!"

It was a position more suited for a martial arts submission or a joint lock. Of course, since Yurika had zero martial arts experience, no joints or necks were actually in danger; the position was just purely erotic.

Squish~♡ Squish~♡

Pressed against her fleshy legs, Yuu could feel the smooth texture of the stockings and the heat of her thighs.

(Gwaaaaah! I’m in heaven!)

Yuu was instantly at the point of explosion.

"There. Have you reflected on your behavior?"

"Nnngh... mmmph..."

Reflecting was the last thing on his mind. The punishment felt so good that Yuu was practically ascending to the afterlife. In fact, he found himself wishing she’d just step on him with her beautiful feet.

(Ugh... this feels too good. Her soft thighs are right against my face... I wish she’d just stomp on me... Wait, wait, wait! Am I a pervert?!)

He tried to force himself back to "wholesome" thoughts. It was a futile effort.

(Wholesome! Be wholesome... Ah! I can almost see her panties from under that skirt! Wait! As a tights-fetishist, should I be focusing on the diamond gusset of the stockings instead of the panties?)

Thanks to Yurika, Yuu’s fetishes were multiplying like rabbits.

"Fufufu~♡ Akashi-kun, I wonder where you're looking?"

Noticing her gaze, Yuu looked up to see Yurika smirking at him.

(D-Dammit! She caught me trying to peek up her skirt!)

Yuu expected a scolding, but Yurika simply unraveled her legs and released him.

"Um..."

"Okay, break time is over, Yuu-kun."

"Eh?"

She didn't reprimand him at all. Yurika just gave him a gentle smile. It seemed that despite calling it a "punishment," it was actually just a little "breather." Yuu thought she was the best sister in the world for giving him such erotic breaks in the middle of studying.

"You surprised me. I didn't know that was a break."

"You need breaks to keep your study efficiency up. But if Yuu-kun looks at my legs or chest with perverted eyes again, I’ll give you an even stricter punishment."

Gulp!

Yuu swallowed hard. If the punishments were that erotic, he was tempted to misbehave on purpose.

"Ah... if I do that, Yuu-kun might just keep being a bad boy, wouldn't he? Okay, then you get a punishment for every page of the workbook you finish!"

"Gwah!"

She had read his mind completely. Sensei Yurika was a master of the "carrot and stick" approach.

"Akashi-kun! Stop dazing off and get back to the next problem!"

Yurika returned to her scary teacher persona.

She was an all-inclusive sister—sometimes a gentle girl, sometimes a scary teacher, and sometimes a sadistic queen. Yuu’s only worry was that her eccentric "training" might leave him with some very permanent, very strange preferences.

※ It’s too late for that.

Between Yurika’s excellent teaching and his own desire for the "punishments" (rewards), the studying progressed at a record pace. The workbook pages flew by, and Yuu’s list of fetishes grew longer. Finally, they reached a good stopping point.

"Okay, finished."

Yuu put down his pen. His desire for the punishments had clearly given him a boost. Yurika gave him a mischievous grin.

"Yuu-kun, you hate it when I want to cuddle in bed, so why do you look so happy when I punish you?"

"Ugh, well, um..."

Yuu realized it himself. (Wait... oh no. Does this make me a masochist?!)

"Oh my~? What’s wrong, Yuu-kun?♡ Were you expecting something erotic?"

"Kuh... nnngh..."

She had hit the bullseye.

Mesmerized by Sensei Yurika’s charms, he had unconsciously accepted the punishments. At this rate, he was going to be completely "trained."

"Akashi-kun! Were you looking at your teacher with perverted eyes? Tell me the truth!"

Sensei Yurika’s eyes narrowed, becoming sharp. She was in "Queen" mode. She raised her leg and slowly ran her toe up Yuu’s thigh.

"Ah!"

A jolt of pleasure like an electricity shot through him, making Yuu’s body shudder.

"Looking at your teacher with such dirty eyes... you really are a naughty boy! I won't let you off easy!"

"Eh? W-Wait, um..."

With an alluring expression on her face, Sensei Yurika’s foot slowly traveled up from his thigh toward his groin. If this continued, something "big" was going to happen. Yuu felt the blood rushing to his lower abdomen.

(Gwaah! I-I can't! I'm gonna hit the limit!)

Thump, thump, thump!

At that exact moment, the faint sound of footsteps coming up the stairs echoed through the hall.

Yurika instantly smoothed down her skirt, adjusted her collar to hide her cleavage, and assumed a perfectly dignified, formal sitting posture.

Knock, knock!

"I’ve brought some tea."

His mother’s voice rang out alongside the knock. Emiko entered the room to find Yurika looking the part of a serious tutor.

"Thank you, Mom."

Yuu was stunned by the speed of her transformation. She had been in the middle of a highly erotic "leg-tease," yet she had reacted to the sound of footsteps and switched personas in the blink of an eye.

Oblivious to the erotic tension in the room, Emiko set the tea on the table and smiled.

"No, I should be thanking you for looking after Yuu’s studies. Oh my, you’ve already finished this much? That’s amazing, Yurika. It’s such a help. By the way, why the suit?"

Emiko tilted her head, looking at Yurika’s professional attire.

"I’m wearing this to maintain a proper 'Teacher and Student' boundary. I don't want us getting complacent just because we're siblings. I might be gentle normally, but when it comes to studying, I’m a Spartan teacher."

"I-I see. How reliable. I guess Yuu’s grades are in good hands."

"Yes, please leave Yuu-kun to me."

Yurika responded with a sharp, strict expression. She was the perfect older sister/tutor.

Meanwhile, Yuu sat with his back to them, stuffing his face with snacks to hide his bright red face, his hammering heart, and his "ready-to-explode" little brother.

(That was too close! That was way too close! Ugh, I can't get my heart to calm down... Why is this erotic sister such a klutz normally, yet so perfect and prepared for stuff like this?)

Once again, Yuu found himself in awe of his sister’s hidden depths.

◆ ◇ ◆

As soon as Yuu stepped into the classroom and took his seat, Takami made her move. She closed in on him instantly, like a predator stalking its prey.

No—more like a "carnivorous girl" on the hunt.

"Hey, Yuu. Hitting the books for the exams?" she asked, leaning in.

"Huh? Oh, yeah. I’m managing," Yuu replied.

In truth, he was being tutored by his beloved "Onee-chan-sensei," but the mere thought of telling anyone was too embarrassing. Yuu kept his mouth shut.

"Hmph. I see. Well, hey... why don't we go to the library and study together after school today?"

"Wait, what?! Ah, no, sorry. I really need to get home early today."

Despite the fact that a "flag" with a female classmate was practically planting itself in front of him, Yuu’s signature style was to snap it in half himself. As a hardcore siscon whose heart belonged solely to his sister, other girls didn't even register on his radar.

Twitch.

For a split second, a vein throbbed near Takami’s temple.

"Listen, you! You’re always in such a rush to get home, aren't you?"

"I mean, I just have things to do..."

"Oh, please. I bet you’re just rushing back to watch more of that smutty anime. What was it? 『Whatever Dorm』?"

"C-come on, can you just forget about that already...?" Yuu groaned.

He desperately wanted her to let it go, but Takami continued to tease him with the "erotic anime" incident. As a girl with a bit of a sadistic streak, she seemed delighted to have found such perfect blackmail material.

"Oh, I know! Then how about this? Let’s have a study session at your house today after school!"

"Wh—Whaaaaaaaaaaaa?!" Yuu sputtered.

He tried to refuse her sudden proposal, but—

"It’s settled! Hehe, I can’t wait. Oh, and you better show me that 『Whatever Dorm』 thing while I'm there!"

Takami was already in full "going to Yuu's house" mode. The more Yuu tried to back out, the more her eyes gleamed with predatory delight. It seemed the very act of watching Yuu squirm was what gave her the most pleasure. She was the type who constantly messed with him just to get his attention.

(Crap, crap, crap! This is bad! This is incredibly bad! If Chuujou-san and Onee-chan ever meet, everything is gonna go to hell!)

Inside Yuu’s head, high-speed simulations began to unfold.

『Yuu-kun, what exactly do you plan on doing after dragging a girl into your room?』 Onee-chan would ask with that smile.

『It’s a misunderstanding! I only love you, Onee-chan! Oneeee-chan!』 I’d cry out.

Then Chuujou-san would chime in: 『Yikes... Yuu, you were a total siscon this whole time? That’s revolting!』

(And then, I bet it’ll go like this...)

『Hey, hey, listen, Ayu! Keep this between us, but Yuu is actually a massive siscon.』

(Aggghhhhhhh! The news that I'm a siscon will spread through the whole school like wildfire!!)

Takami stared at Yuu with an exasperated expression as his internal monologue dragged on.

"Hello? Yuu! What are you spacing out for? Anyway, it’s a date. We’ll talk details after class."

While Yuu was lost in his delusions, the study session at his house had been finalized without his consent.

◆ ◇ ◆

In a bathroom stall, Yuu stared at his smartphone screen, agonizing over his options.

(It’s no use trying to talk Chuujou-san out of it now. She looks like she’d follow me home by force if she had to. My only choice is to give Onee-chan a heads-up to avoid a total disaster... But how do I even phrase it? No matter what I say, I only see a future filled with trouble!)

Steeling his resolve, Yuu tapped out a message.

【I’m bringing a classmate home after school today.】

Ping!

The reply from Yurika came instantly.

【Oh, a friend is coming over? Well, I’ll have to prepare some hospitality. Oh—it’s not a girl, right?】

Yuu felt a wave of silent pressure emanating from that last sentence. With a trembling hand, he sent his reply.

【It’s a girl.】

No reply.

(O-oh no! Did I make her snap?!)

Ping!

After a short silence, the notification sound rang out. Yuu checked the screen with bated breath.

【Yuu-kun! If a young boy and girl get stuck in a private room together, they’ll start flirting, and smooching, and putting that into there and this into that! It’s absolutely forbiddennnnnnn!】

It was the exact reaction he had expected. She was completely ignoring her own behavior, speaking as if every girl on the planet was purely out for lewd encounters.

【We aren't doing anything! We're just having a quiet study session, so Onee-chan, please just stay calm, okay?】

All he could do now was leave it to fate and pray that nothing went wrong.

◆ ◇ ◆

After school—

Yuu was walking home with Takami. To any other guy in class, being seen with the popular Takami would be a dream come true. However, Yuu’s heart was heavy with the dread of a potential collision between her and Yurika.

"So, what’s your place like, Yuu? Do you have any siblings?" Takami asked, peppering him with questions.

"It’s just a normal house. I have an older sister, though."

"Huh, an older sister? Does she look like you?"

"N-not really, I guess..."

If he let it slip that they weren't blood-related, she’d probably start digging for details. Yuu kept the fact that Yurika was his step-sister to himself.

Just as they were about to reach his front door, an unexpected voice called out from behind them.

"Oh, it has been a while, hasn't it, Akashi-kun?"

The two of them turned around to see a beautiful girl standing there, her silky black hair fluttering in the breeze. It was Rokujou Aoi, a girl notorious in Yuu's mind for being nothing but trouble.

"You! Rokujou! What the hell are you doing here?!" Takami reacted before Yuu could even open his mouth.

"Oh? Was it... Kitchen-san, was it?" Aoi asked airily.

"It’s Chuujou!"

T/N: Kitchen-san (Chubou-san): A pun on Takami's family name, Chuujou (中将). Aoi intentionally misreads it as Chubou (厨房), which means "kitchen.”

Aoi "misremembered" the name as usual, though this time the meaning had drifted into an entirely different territory.

"Rokujou-san... Why...?" Yuu stared at her, utterly aghast.

"I just happened to be walking through this area when I caught sight of you two. It was purely coincidental, I assure you."

Aoi emphasized the word "coincidental" with suspicious intensity. Yuu felt a wave of dizziness wash over him. Dealing with Takami was hard enough, but now the ultimate troublemaker, Aoi, had joined the fray. He could practically hear the sirens of an impending disaster.

Oblivious to Yuu’s mental state, the two school beauties continued their verbal sparring.

"You totally followed us! Quit being a creepy stalker!" Takami barked.

"My, you’re as unrefined as ever. Akashi-kun, why don't you have a study session with me instead of... this?" Aoi countered.

"What do you mean, this?! And how do you even know about the study session?! You are a stalker!"

Their bickering showed no signs of stopping. At this rate, one might even suspect that Aoi actually liked Takami. It always seemed like Aoi went out of her way to mess with Takami just for the fun of it.

Incidentally, Yuu happened to be a fan of the yuri genre.

"Honestly! Give it a rest already, Rokujou!"

"Oh? I’m perfectly fine with it just being Akashi-kun and me."

"Like hell that’s happening!"

In the end, it was decided that all three of them would study together. Yuu’s opinion, of course, was completely ignored. Behind Yuu, the two girls were practically emitting sparks, their killing intent clashing like a street fight.

The thought of introducing these two volatile girls to his sister made Yuu’s feet feel like lead.

(Ugh, how did it come to this? I just wanted to get home early and play with Sis today...)

Even now, Yuu's head was filled with thoughts of Yurika.

(I know she’s been going off the rails lately, kissing me right in front of our parents or doing weird stuff under the guise of "punishment." But... honestly, it’s kind of becoming a habit... actually, I think I might like it...)

He wasn't entirely against it.

◆ ◇ ◆

"I'm home..."

Yuu entered the house followed by the two girls.

"Pardon the intrusion!" Takami chirped.

"Thank you for having me," Aoi added.

The two of them looked around the entryway with keen interest. Just as Yuu was about to lead them to his room on the second floor, the living room door swung open, and Yurika made her grand entrance.

"Oh, S—pffft!"

Yuu nearly choked. His sister had appeared, but for some reason, she was in full cosplay as a "sophisticated, capable office lady."

It was similar to her female teacher outfit from the other day, but this time she was wearing glasses and a sleek pantsuit. She was clearly trying to exude a professional "OL" aura. He had no idea what she was thinking.

"Yuu, you're back. And who might these be?"

She seemed to be fully committed to the role, even her tone of voice screaming "capable career woman." The conversation moved forward while Yuu remained frozen in confusion.

"U-um, I'm Chuujou Takami. I'm his classmate."

"I am Rokujou Aoi. It is a pleasure to meet you."

The two girls bowed, looking visibly nervous.

"I am Yurika, Yuu's older sister. Thank you for looking after my little brother."

Yurika’s voice was dignified and sharp—a total 180 from her usual doting self. As they spoke, Takami and Aoi were completely overwhelmed by Yurika’s beauty and her captivating figure. She possessed a perfect appearance paired with an aura of competence. For these two, trying to compete with such a perfect woman felt like a lesson in futility.

In particular, Aoi—who was widely considered the most beautiful girl in her grade—was left stunned by a certain difference in their proportions.

(W-what incredible curves... Dammit... I’ve lost...)

While Aoi had a slender, lithe frame, her chest was equally "slender" and modest. Seeing Yurika’s massive breasts practically straining against the fabric of her suit as if defying gravity, the flat-chested Aoi couldn't help but feel a crushing sense of defeat.

(Heh. My victory...)

Yurika puffed out her chest triumphantly. Yuu watched this silent, instantaneous "Boob Battle" and couldn't help but feel his sister was being incredibly childish.

(O-Onee-chan... why are you trying to compete with middle schoolers? That’s a bit immature, don't you think?)

Leaving aside the inscrutable Yurika and the overwhelmed girls, Yuu just prayed the study session would end without incident.

The initial bravado Takami and Aoi had displayed vanished; they were completely suppressed by Yurika's presence and fell silent. They moved to Yuu’s room, and once the three of them were alone, the conversation finally sparked back to life.

"Whoa, Yuu! Your sister is kind of scary! She’s like a strict teacher or something," Takami whispered.

"Ugh... y-you think so? Maybe it’s because she wants to be a teacher...?" Yuu played along. He couldn't risk saying anything else when he had no idea what Yurika might do next.

"Oh, so she is going to be a teacher."

Meanwhile, Aoi was still in a daze.

"The... the boobs..."

The word "boobs" actually escaped the beautiful girl's lips. It seemed the prideful Aoi had tasted defeat for the first time in her life. Since it looked like it was going to be a hassle to deal with, Yuu decided to just leave her be.

Knock, knock!

"Yuu, I'm coming in."

True to Yuu's predictions, Yurika appeared with tea almost immediately. He knew she’d find an excuse to sniff out their relationship. Sure enough, after setting the tea on the table, Yurika began her interrogation regarding Yuu's social life.

"So, what exactly is your relationship with Yuu?"

While asking with feigned casualness, Yurika was carefully memorizing their faces and names.

(This is the girl who was with Yuu-kun at Wack before. She is definitely a Person of Interest! And the other one said her name was Aoi... she’s the one who kept calling him. Another Person of Interest!)

Takami and Aoi had officially been flagged as threats.

"Um, well... w-we're friends," Takami replied, hesitating over the word. Her innocent reaction made it look as if she were aiming for something more than friends.

"I am simply a classmate," Aoi stated firmly.

However, she emphasized "classmate" so much that it made one suspect there was actually something more going on. To Yurika, any girl approaching Yuu was a high-level threat.

"Onee-chan, go back downstairs. We’re trying to study," Yuu said, trying to push her out. But Yurika wouldn't budge an inch.

"Studying is a wonderful thing. However, there is one thing I must say first. You girls are at a critical age regarding your education and future paths. I'm sure you’ll be fine, but as long as I am here, I will not tolerate any impure relationships or scandalous behavior!"

Yurika’s statement was a goldmine of hypocrisy. (The most scandalous person here is you, Onee-chan!) Yuu shouted in his head.

"I get it already. We'll be fine."

"Good. If you say so. Also, I have some snacks, so come down and get them in a bit."

"Yeah..."

Yuu followed his sister down the stairs.

Once they were alone in the dining room, Yurika shed her "OL" persona and returned to her usual self. She pinned Yuu against the wall.

Thump!

"Yuu-kun! Why did you bring two of them? Are you two-timing me?!"

"I-I’m not! I told you, they're just classmates!"

She pressed in so close their chests were almost touching, forcing Yuu to lean back as far as he could. Up close, the sight of his sister in glasses was a direct hit to his preferences, and his face turned bright red.

(Gah, Onee-chan in a suit and glasses is the best! The intellectual vibe of the glasses, the tight pantsuit... it’s too sexy! All you glasses-fetishists across the nation... count me in as one of your own starting today!)

Thanks to Yurika, Yuu had discovered a brand new fetish. However, Yurika completely misread his reaction.

"Wait... Yuu-kun, do you actually prefer sailor uniforms?"

"Huh?"

Seeing Yuu bring home girls in sailor-style school uniforms had led Yurika to a misunderstanding.

"I see... ♥ If you want, I can wear a sailor uniform for you too, okay?"

"No, no, no, what are you even saying?"

"I've got it! Next time, I'll cosplay in a sailor uniform and we can cuddle in bed together! ♥"

"G-gah...!"

Yuu’s heart raced at the mental image of Yurika in a sailor uniform. A mature woman in a school uniform possessed a completely different, dangerous allure compared to actual middle schoolers.

"A-anyway, we're studying, so don't come in!"

"If you aren't doing anything 'weird,' there shouldn't be a problem if I come in, right?"

"Ugh... w-we aren't doing anything."

As Yuu picked up the snacks and prepared to head back up, Yurika grabbed his arm.

"Yuu-kun, you forgot something. Chu ♥"

She embraced him gently from behind, and as he felt her soft curves against his back, she kissed him on the cheek, dangerously close to his lips.

Fwoosh!

Yuu’s face turned beet red in an instant. The sneak attack left him completely rattled.

"Hehe ♥ Off you go."

"Urrrgh..."

Whether she was conscious of it or not, Yuu was being perfectly trained by her kisses. She truly was a sinful woman.

When Yuu returned to the room, Takami immediately began prying.

"Yuu, did something happen? Your face is all red. Are you okay?"

"Eh? O-oh, really?"

"Did your sister scold you or something?"

It seemed they had misunderstood. Both Takami and Aoi were convinced that his sister had a terrifying personality. Since explaining would be a hassle, Yuu decided to just roll with it.

"Yeah, my sister is scary, so please don't get on her bad side."

With that, the study session truly began. However, the three of them were a bit too large for the small low table. They were forced to sit shoulder-to-shoulder, each of them nervously opening their notebooks.

Aoi, being a top student, breezed through the problems. On the other hand, Takami seemed to be struggling a bit. Catching sight of this, Aoi let out a small, mocking chuckle.

"My, Ms. Shinjo. It seems your academic skills are just as unrefined as your personality."

"What’s that supposed to mean?! And it’s Chuujou!"

It was practically a routine now—Aoi "forgetting" her name. It was enough to make one wonder if they were actually secretly close.

"Are you two actually friends?" Yuu asked.

"As if!" Takami barked.

"Not a chance!" Aoi echoed.

They answered Yuu in perfect, rhythmic unison.

"Whew, let's take a break. Maybe I'll go looking for Yuu's hidden stash of dirty books?" Takami suddenly suggested.

"Whoa, hold it right there!"

Yuu grabbed Takami’s hand to stop her.

"Come on, it's fine! Show me that 『Whatever Dorm』 thing! I know you have something erotic hidden here!"

"I told you, no! It’s not here!"

Takami tried to rummage under the bed, and Yuu desperately tried to restrain her. To any outsider, they looked like they were flirting.

"Hey, Yuu! Ah, stop! You’re touching me too much! Pervert!"

In his panic to stop her, Yuu had wrapped his arms around her waist from behind. He didn't have a single lewd thought in his mind, but his desperate attempts to restrain her looked exactly like he was hugging her.

Click.

The door suddenly swung open.

"Ah..."

Yuu and Takami froze as they were met with the piercing gaze of Yurika, whose brow was twitching dangerously.

"Yuu! Impure relationships are—"

As expected, Yurika had completely misunderstood.

"Fine! I will stay right here and watch. No scandalous behavior allowed!"

The two of them were given a stern lecture and forced to study under Yurika’s watchful eye. Yurika sat in Yuu's desk chair, crossing her legs and staring at the three of them. It felt exactly like a classroom.

However, compared to the time she had slapped her friend Maki while crying, perhaps Yurika had improved slightly.

(Yuu-kun... Honestly, I can’t take my eyes off him for a second. He’s at that age where he just wants to do lewd things the moment I look away. I wonder... should I be the one to handle his 'release management' myself?)

Yurika was thinking something truly outrageous. She was completely out of bounds. Rather than improving, she had become even more dangerous.

(Note: It’s safe as long as she only thinks it.)

Perhaps getting bored of just watching, Yurika began making the rounds to check on their progress.

"Rokujou-san, you’re doing wonderful. All of these are correct."

"Oh, ah, thank you."

Aoi was an excellent student, so there wasn't much to teach. Yurika simply offered a few tips.

"This method would be faster, though."

"Oh, you're right. Thank you very much."

The way Aoi looked at Yurika had changed completely. After her initial defeat, Aoi had tucked away her haughty attitude and was now obediently following Yurika’s guidance. Next, Yurika looked at Takami’s work.

"If you do this here, the 'y' cancels out. Then, if you substitute it back into this side—"

"Oh! I got it!"

"Good. Try applying that to the other problems."

"Thank you! Sis, you're really good at teaching!"

Takami stared at Yurika with a look of pure admiration. Being taught in such an easy-to-understand way had clearly sparked some idol-like worship. Yurika, however, was internally nitpicking Takami’s choice of words.

(Oho? 'Sister-in-law'? I don't recall giving you the right to call me your sister-in-law!)

She was thinking like a petty mother-in-law. If Yuu and Takami ever actually got married, the friction between the sister-in-law and the wife would be catastrophic. Not that Yurika would ever let that happen.

"For this one, align these coefficients—"

"Yes, ma'am."

Despite her petty thoughts, Yurika continued to teach them properly. She was kind in her own way.

But as Yuu watched them and began to relax, the "Erotic Sister's" demonic hand crept toward him. While Yurika was looking at Takami’s work on the right, she used her left hand to stroke Yuu’s thigh.

Stroke, stroke, stroke...

Yuu, who had been relieved that his sister was behaving, was sent into a panic by her sudden assault.

(O-Onee-chan! Stop doing lewd pranks right in front of my classmates!!)

Taking advantage of the fact that her hand was hidden by the table, Yurika was stroking a very dangerous area. She might have intended to just pet his leg, but that area happened to be his "third leg."

Yuu buried his face in his textbook, trembling as he tried to endure it.

(That’s too dangerous! Do you even know what you're touching?! Crap, if this keeps up, something terrible is gonna happen! I can't... I can't let it explode right in front of Chuujou-san and Rokujou-san!)

There was no way his state would go unnoticed.

"My, Akashi-kun, is something the matter?"

"Yuu? Are you feeling okay?"

Worried by the sight of Yuu face-down and trembling, Aoi and Takami spoke up.

"I-I just... need the... bathroom..."

Yuu hunched over, desperately holding something back as he bolted for the toilet.

Stomp, stomp, stomp! Slam!

The moment he slammed the bathroom door shut, he let out a sigh of pure relief.

"Urgh! I made it... phew."

It was a close call.

Click.

"Yuu-kun, are you okay?"

Yurika’s worried voice came from the other side of the thin door. She had obviously followed him out of concern.

"I-I-I'm fine! Just go back!"

"But I'm worried about you..."

"Ugh! Huff... Phew..."

"Yuu-kun...? What are you doing?"

"I-It’s nothing!"

Despite her lewd streaks, Yurika could be surprisingly pure when it came to certain things. She had no idea about the biological phenomena men faced and was genuinely, innocently worried.

◆ ◇ ◆

Thanks to his private tutor, "Yurika-sensei," Yuu’s exam scores shot up significantly. Yurika’s thorough and easy-to-understand guidance, combined with her "rewards" disguised as "punishments," had produced visible results.

The side effect, however, was that Yuu’s repertoire of niche fetishes had grown alongside his grades.

Incidentally, Takami’s grades improved as well. She, too, had come to deeply respect the beautiful, charming, and talented Yurika. Ironically, Yurika’s plan to keep other girls away from Yuu had resulted in those very girls becoming fond of her and drawing closer.

After the tests were returned, the topic became the highlight of the Akashi family dinner table, with Emiko absolutely delighted.

"Yuu, this is amazing! Your grades have improved so much. It’s all thanks to Yurika."

Yurika looked pleased but didn't forget to praise Yuu.

"No, it’s because Yuu-kun worked so hard. He was very serious during my lessons."

"I'm so glad Yurika became Yuu’s Onee-chan. She’s kind, smart, and cares so much about her brother. Don't you agree, dear?"

Mikiya, prompted by his wife, also looked impressed.

"Yes, Yurika. It’s wonderful of you to look after Yuu-kun's studies."

"It really is. Though, it sounds like her teaching style is a bit of a 'Spartan' regime with strict discipline," Emiko added.

At the mention of "Spartan," Mikiya’s expression clouded over.

"Wait, Yurika... I know being firm is necessary sometimes, but don't you think being too strict might be counterproductive?"

As a man with a gentle personality, Mikiya was naturally opposed to harsh, "Spartan" education. However, Yurika puffed out her chest with a determined "Hmph!"

"Father, I am only being strict because I care about Yuu-kun's future. If I feel he isn't putting his heart into his studies, I am fully prepared to deliver a harsh 《Punishment》!"

Twitch!

Yuu, who had been listening in silence, had a physical reaction to the word "punishment." Having been punished by his sister so many times, the mere sound of the word sent a surge of heat straight to his core. He was practically conditioned.

(Ugh, Onee-chan... please don't talk about 'punishments' in front of our parents. It makes me remember the erotic ones and your alluring thighs.)

Yuu’s academic boost was, in fact, almost entirely due to those erotic punishments.

The conversation between Mikiya and Yurika continued.

"Still... kindness is just as important as strictness."

"Don't worry, Father. I make sure he gets plenty of 'breather' time too."

Twitch, twitch!

Yuu’s body reacted again. He was on edge, terrified that Yurika might accidentally let slip the details of the "punishments" or the "breather" activities.

(Ugh... I'm so sorry! Dad, Mom! I'm having erotic delusions about my step-sister, I'm using her as 'material' at night... I'm way past the point of no return! I'm harboring lewd, perverted, and utterly scandalous feelings for your daughter!)

Truly, they were two of a kind.

"Yuu-kun, if Yurika is ever being too strict and it’s becoming painful, come talk to me in secret, okay? I’ll give her a talking-to," Mikiya said, taking Yuu’s side. He really was a kind step-father.

"O-okay..."

He appreciated Mikiya’s kindness, but he could hardly say, "Actually, she’s an erotic tutor sister." Caught between his step-father’s kindness and his step-sister’s lewdness, Yuu could only fidget in discomfort.

Yurika, watching their exchange, finally spoke up.

"Honestly! I told you it’s fine, Father. I’m strict with the studies, but I’m perfectly sweet the rest of the time, aren't I?"

"Well, if you say so." Mikiya was finally convinced.

After dinner, while Yuu was in the bathroom brushing his teeth, Yurika crept up behind him without a sound.

"Yuu-kun."

"Whoa! W-what?"

Yuu jumped as she hugged his defenseless back.

"Yuu-kun, you mustn't tell them what the punishments are, okay?"

"L-like I could ever tell them that!"

There was no way he could admit his sister’s punishments were way too erotic.

"That’s good. I mean, Yuu-kun, you spend so much time staring at my legs. It just makes me want to punish you even more."

So his "glances"—no, his "staring"—at her alluring tights had been completely spotted.

"Come on, Yuu-kuuun ♥ Punishments are great and all, but we should cuddle in bed together toooo~"

"I told you, we can't. Our parents would find out."

"Then, then... it’s okay when our parents aren't here, right?"

"Ugh, I mean..."

Yurika knew. She knew their parents were planning a trip for just the two of them soon. She had already decided she was going to flirt with Yuu all day long while they were gone.

(Hehehe ♥ Once they go on their trip, it’ll be just the two of us all night. Unlike our honeymoon trip, Yuu-kun has grown up so much... maybe he’ll even be the one to make a move on me! He’ll say, ‘Onee-chan, I can't hold back anymore!' or something! Kyah!)

Yuu looked at his sister’s "hehehe" face and knew she was plotting something lewd.

(Onee-chan... you're so beautiful, and yet that erotic imagination of yours leaks right onto your face. She is definitely thinking about something weird...)

◆ ◇ ◆

Returning to her room, Yurika began rummaging through the back of her closet for some old clothes.

"Found it! Here we go!"

It was the sailor uniform she had worn back in middle school. As she held it up, her mind drifted back to the recent study session—specifically, the moment that had convinced her beyond a shadow of a doubt that Yuu had a major sailor uniform fetish.

"That Yuu-kun... getting all excited just because his classmate was wearing a sailor outfit. Just you wait."

Indeed, Yurika was plotting to don the uniform herself to lead Yuu into temptation.

(Hehehe... If I wear this when our parents are away on their trip and it's just the two of us... Yuu-kun won't be able to hold himself back...)

"I should try it on first."

Yurika stripped down and attempted to slide her arms through the sleeves.

"Huh? Ungh... ngggghhh..."

The middle school uniform was far too small. It was a struggle just to get into it. The fabric across her chest was so tight it looked ready to burst at the seams, and the skirt was so short her backside was practically peeking out.

"..."

She stood frozen before the mirror for a long moment.

"I haven't gained weight! I haven't! I-I've just... grown. Especially my chest..."

Despite her incredible figure, a middle school uniform was a bridge too far. What was once a wholesome school outfit now looked obscenely suggestive on her mature frame. While that might have been ideal for seducing Yuu, the sight in the mirror was so embarrassing she felt she could never show it to another living soul.

"This is... maybe a bit too lewd. It might be bad if I turn Yuu-kun into a total deviant."

Granted, she had already exerted a questionable influence on him, but even she felt there were limits. Being this "bursting at the seams" was liable to unlock some truly strange fetishes.

"Hmm. My high school uniform is a blazer, so I guess I'll just have to 'one-click buy' a cosplay outfit online..."

Yurika was apparently determined to make the sailor uniform dream a reality.

(I know! What if I pretend to be Yuu-kun’s classmate? A scenario where we go to school together would be perfect. We’d walk to and from school together ♥ We’d be together for sports day and the culture festival ♥ We could even go on a school trip together! ♥)

Yurika harbored a secret desire to experience school life alongside Yuu. Just imagining the "naughty things" they could do together in the PE storage room made a wave of heat pulse through her core.

(Haaah ♥ Yuu-kuuuun ♥ You can't ♥ Not in a place like this... ♥)

Knock-knock-knock!

Yurika, currently stuffed into a skin-tight sailor uniform and clutching her lap as she indulged in her lewd fantasies, was jolted back to reality by the sound at her door.

"Huh?"

"Onee-chan? I'm coming in."

"Wait—no! Don't—!"

Click.

The door swung open before Yurika could stop him. Yuu was suddenly face-to-face with his self-proclaimed "Middle Schooler Onee-chan" in the most scandalous state imaginable.

"Oh..."

Yuu looked as if he had just witnessed something he was never meant to see. Without a word, he slowly reached for the handle and closed the door.

"Don't just close it without saying anything!" Yurika shrieked.

She desperately caught the closing door and dragged Yuu into the room. If she let him leave now, he’d surely spend the rest of his life thinking she was an "Erotic Sister" who played perverted dress-up games alone in her room.

"T-this... this isn't what it looks like... I was just... feeling nostalgic, you see?"

"No, it's fine. I understand your hobbies, Onee-chan."

"It's not a hobby! I mean, it's not just a hobby! Well, it is a hobby, but..."

For Yuu, his sister’s uniform-clad appearance was a direct hit to his vitals. He struggled to find a place to look, glancing away while catching stray peeks. It was too erotic to look at directly, yet she looked undeniably cute and it suited her perfectly.

(o-Onee-chan... I thought she just liked cosplay, but she’s secretly doing the sailor uniform thing in her room too... It’s a bit perverted, but I love that about her!)

Thanks to Yurika, another of Yuu's fetishes had been—no, the uniform fetish had been there all along. He had been smitten by Yurika’s high school uniform from the moment they met, and he had loved it ever since.

"Anyway, I'll be going now."

"Yuu-kun, don't you dare tell anyone about this."

"Well..."

"Honestly! To make sure you keep your mouth shut, I'm going to give you a extra-harsh 《Punishment》 right now!"

She was using "punishment" as an excuse for everything now.

"Hey! Don't hug me while you're dressed like that!"

Clad in the bursting sailor uniform, she pulled him into a tight embrace. Yuu felt every soft, rounded part of her pressing against him.

"Yuu-kun, if you raise your voice, our parents will find out," she whispered into his ear.

"Urgh..."

Yuu fell silent. The threat of their parents finding out made him completely submissive to his sister’s whims—even though Yurika was the one who would actually be in trouble if they were caught.

"Hehe ♥ Be a good boy now, Yuu-kun."

The "Classmate Sister's" harsh punishment was about to begin. An outfit that was supposed to represent innocence and order had become agonizingly erotic on Yurika’s captivating body. His actual female classmates couldn't even compare. Yuu was so flustered he couldn't even look her in the eye.

"U-um, Onee-chan..."

Being held so close by Yurika in her sailor uniform, Yuu was enveloped by her soft touch and pleasant scent. He was on the verge of total surrender.

(Ugh, Onee-chan. I love you too much... I just want to grab you, bury my face in your chest, breathe in your scent, and cover you in kisses!)

Unaware—or perhaps perfectly aware—of Yuu's imminent collapse, Yurika showed no signs of letting up her assault.

"Ehehe ♥ I wonder what’s wrong with Yuu-kun? ♥"

She had completely forgotten her original plan to seduce him into making a move. Right now, she just desperately wanted to flirt with her beloved little brother. She felt like she could stay locked in this embrace for twenty-four hours straight.

"Hey, hey, Yuu-kun. What kind of punishment would you like?"

Apparently, she was going to let Yuu choose the details. She looked more than willing to provide even the most erotic of penalties.

"T-that's not right..."

"Aw, come on! Let's do a punishment! ♥ Chu ♥"

She gave him a sudden kiss on the cheek. Yuu’s body gave a startled jolt.

"Ehehe ♥ You're twitching, Yuu-kun."

Caught up in the moment, Yurika began peppering him with kisses. Every time Yuu reacted, her heart soared with joy.

" Chu ♥ Chu ♥ Hehe, you're so cute! ♥ Chu-chu ♥"

She targeted the dangerous areas—the corners of his lips, the sensitive skin near his ears. With every kiss, Yuu felt his heart and soul being dyed in his sister’s colors. He was already at his limit, yet she seemed determined to drag him even deeper into the abyss of pleasure.

(Ah... Onee-chan's kisses feel too good. No matter how many times I think I've reached my limit, she just keeps pushing past it. There's no going back now... I can't imagine a life without her.)

"Hey, Yuu-kun ♥ Can I kiss you on the lips?"

Yurika had finally decided to go for Yuu’s first kiss. Her own desire had reached a boiling point; she desperately wanted to taste him. She wanted a mature kiss, with their tongues intertwining and dancing together.

"N-N-No! Absolutely not!"

Yuu refused. It took every ounce of his willpower to say those words.

"Ehh?! Why not? Don't be such a stingy brat."

"I told you, no. That kind of thing is for people who are actually dating... for lovers."

Yuu wanted to kiss her more than anything in the world. But he believed it should only happen after a proper confession, once they were officially a couple.

"Then, then... is it okay as long as it's not the lips? Between a kiss on the lips and a kiss anywhere else, which do you prefer?"

"Well... obviously anywhere else..."

Grin!

A triumphant smile spread across Yurika's face.

Yuu had walked right into her trap. When people are faced with a large request and refuse, they often find it much harder to refuse a second, smaller request. They think, Well, I already said no once, I guess I can allow this much.

But in reality, that "smaller" request can be even more outrageous.

This was the Yurika-style 《Art of War》—

Undetectable as the movements of a Wise Sister.

"Wait? Huh?"

Question marks floated above Yuu's head, but it was already too late. He had just given the Erotic Sister permission to kiss him anywhere except his lips. His fate was sealed; he was going to be covered in kisses.

"Mmmph ♥ Yuu-kun! ♥ Chu ♥ Chu-chu ♥ Slurp ♥"

"Whoa—ngh!"

A storm of kisses descended upon Yuu's ears. She kissed the sensitive area around them, his earlobes, and occasionally her tongue would stray into the ear canal itself.

"H-hey! You're going too far!"

"Ehh? But Yuu-kun said it was okay."

Carried away by her momentum, Yurika’s kisses moved down to his neck. For Yuu, who adored his sister, the sensation was pure, unadulterated ecstasy. His body was practically convulsing from the pleasure. Yurika, unable to contain her own excitement, squeezed him tight with both arms.

"So, have you decided on the punishment you want?" she whispered sweetly into his ear.

"Nnngh..."

Punishment was the last thing on his mind; the kisses themselves had become the ultimate penalty. The fact that a mere kiss could make him melt with such happiness was less about technique and more about the overwhelming love they shared. Their feelings were running wild, making everything they did feel incredible.

"O-Onee-chan..."

"Yuu-kun, right now I'm not your sister. I'm your classmate, Yurika-chan."

"Gah... There's no way a classmate could be this sexy."

"You have to call me Yurika-chan."

"I can't."

"Honestly! Then I'll just have to pick the punishment myself!"

The "Sister" formerly known as "Classmate Yurika-chan" was going to choose his fate.

"Hmm... okay! Then I'm going to kiss your tummy!"

"Huh?"

"That's right! I'm going to give Yuu-kun's tummy lots and lots of kisses! ♥"

It wasn't even a punishment anymore; she just wanted to kiss him.

"That's way too niche! No!"

"It'll be fine. I won't make it hurt~"

"That doesn't even make sense!"

"Yuu-kun, if you're too loud, they'll find us."

"Ngh...!"

Yuu’s textbook reaction made Yurika's heart flutter.

(Y-Y-Y-Yuu-kun! That expression is too much! If you give me such an inviting reaction, your Onee-chan isn't going to be able to control herself! ♥)

Yurika closed in on Yuu, who was desperately covering his mouth to keep from making a sound. Her tension was at an all-time high. In that moment, she was like a rampaging Succubus Queen. Yuu, her prey, was about to have his life force drained to the very limit.

Flip—

Yurika lifted Yuu’s shirt. His defenseless stomach was exposed, and a flushed Yurika descended with her lips puckered.

Thump-thump-thump-thump...

" Chu ♥"

Yurika’s beautiful lips made contact with Yuu’s abdomen. A sensation like an electric current surged through him, making his body jump.

"Mmmmnnh...!"

Yuu bit back a cry, desperately trying to keep himself from ascending to the heavens. Since Yurika was sitting on his lower half, he couldn't even move to escape her touch.

(Onee-chan... I might be at my limit... I've tried so hard to endure this, but I can't... not like this...)

Smack-smack-smack-smack-smack-smack ♥ Lick ♥ Smack-smack-smack-smack-smack-smack ♥ Lick ♥

Even though Yuu was clearly at his breaking point, Yurika began a rapid-fire barrage of kisses, occasionally weaving in a "lick" for a devastating combo. It was a high-level, high-speed chain of attacks that would make a pro gamer blush. A ruthless playstyle that hammered him just as he was about to fall. Yurika didn't mean any harm, of course; it was just love running out of control.

"Gah... haaaah..."

"Yuu-kun ♥ Yuu-kun ♥ Yuu-kun ♥ Yuu-kun ♥ Chu-chu-chu-chu ♥"

(I'm done forrr!)

Thoroughly melted by the barrage of kisses and with Yurika’s large, soft breasts resting on his lap, Yuu felt like he was about to depart this world entirely for the great beyond.

" Lick ♥ Yuu-kun ♥"

Yurika’s hand moved to the waistband of Yuu’s pants. Just as she was about to pull them down, she stopped herself and let out a sharp breath.

(Yuu-kun... I want to... I want to go all the way... But...)

Yurika pulled away from Yuu and gently straightened his shirt for him.

"There. Punishment over."

Her face had returned to its usual gentle smile. In truth, while she was smiling on the outside, she was exerting blood-curdling levels of self-restraint on the inside. It was precisely because she loved and cherished Yuu so much that she felt she couldn't be the one to cross that final line. She might have been acting wild, but her reason was still intact.

"Onee-chan..."

"Y-You mustn't do lewd things, okay! Or the P-Policemen will arrest you!"

Even though she was the one doing the lewd things, she was lecturing Yuu as if he were the one forbidden from them. She even brought up his old "Policeman" dark history.

"P-please stop with the 'Policemen.' That's a dark part of my past."

"Ehh? But I think you looked cool. Policeman Yuu-kun."

"Gah!"

The "Policemen" thing didn't matter, but Yuu’s body was aching from the extreme arousal she had caused. Both of them sat side-by-side on the bed in an awkward silence. They were both stuck in a "standby" state, their desires simmering.

Just then, Emiko’s voice echoed from the stairs.

"Yurika~! Go ahead and take your bath first!"

"O-Okay!" Yurika shouted back through the door.

"Well... I-I guess I'll go take my bath now."

"Y-yeah... I'm going back to my room."

Yuu, who was at his absolute limit, had "things" to take care of in his room. Namely, his own "internal combustion."

"Oh, wait! Uhh...?"

As Yuu tried to leave, he heard Yurika fidgeting and mumbling behind him.

"What's wrong?"

"Yuu-kuuuun... the clothes are too tight and I can't get them off. H-help meeee~"

"Seriously...?"

Yuu turned around to find his "Erotic Sister" completely trapped by the skin-tight uniform, her arms raised in the air as she struggled to move. Her underwear and armpits were fully visible—it was an incredibly suggestive sight.

"Onee-chan... are you an idiot?"

"That's so meeeean! Yuu-kun, help me!"

Yuu, who was already seconds away from "firing," found himself forced to help his way-too-erotic sister out of her clothes while witnessing her most shameful state.

(I guess I have no choice... my airheaded sister... sniff-sniff...)

Quietly admiring Yurika’s cute underwear while occasionally catching a scent from her armpits, he helped her out of the tight sailor uniform. It felt a little bit like a reward.

(Heh. I love my airheaded sister too!)

Yuu was left with a complicated mix of emotions: wanting to stare at his silly sister forever, wanting to rush back to his room to "handle things," and being happy that he now had even more "material" for later.