Chapter 3: The Two-Person Habitable Zone

Most of the work for the Astronomy Club happens before you ever look through a telescope.

You spend a lot more time staring at weather forecasts, moon phase calendars, and star charts than you do at the sky. Since the school roof isn't a great spot for observation, we usually head to a campsite in the suburbs. Planning those trips around meteor showers and club members' schedules takes a lot of coordination.

Miharu and Kunitomo are both in the Track and Field Club, so I have to adjust our plans to make sure they don't clash with their meets. As a result, the upcoming camp ended up falling right on Miharu’s birthday.

"Hey, Ryuuichi-kun. Today’s club meeting is for the camp next month, right? I thought we finished most of the planning last week. Is there anything left to do?"

Miharu had come over to me after school. As she said, today was meant for final adjustments for the Astronomy Club’s biggest event: the overnight observation camp at the suburban campsite.

Our main goal for the trip was to observe and photograph the Geminids. To secure our budget for the next school year, we needed to show some actual results—searching for undiscovered comets was a noble goal, but we needed the kind of "standard" club activities that school boards actually liked.

"Even if it’s just a check-in, I’ve got everyone's schedule locked down, including Sensei’s. The campsite is already booked, so today we’re just double-checking the equipment list and the timeline for the day. Nothing too crazy."

Miharu looked apologetic and pressed her hands together. "In that case, is it okay if Yuria skips today? Her time trials are coming up, and she really wanted to get some extra practice in."

"Yeah, no problem. Sensei’s stuck in a faculty meeting today too, so it’s fine. Are you sure you shouldn't be over there with her? I don't want the Astronomy Club to be the reason your times drop."

Miharu smiled and shook her head. "I’m fine. Really."

"You sure? You don't have to push yourself. I’d feel terrible if this messed with your athletics."

Miharu was always worrying about me, but I often wondered if she was suppressing her own desires to stay by my side.

"I’m really okay. Don't worry. Actually... I think I’m lucky that we get to be alone together. ...Ah, j-just kidding!"

She tried to play it off as a joke, but the way her face turned beet-red told me exactly how much she meant it. Faced with that shy, radiant smile, I couldn't bring myself to press her any further.

"Well... if you say so. I’m glad you’re here."

"Hey... since Sensei isn't coming, why don't we do the planning somewhere else?"

I didn't have any objection to that. "Sure. We’re just going to be talking, anyway. Should we go to the usual family restaurant? Or maybe a cafe? It’ll be quieter there."

Miharu shook her head, her face flushing even deeper.

"Since we have the chance... why don't you come over to my house again?"

The suggestion caught me off guard. I fumbled for a response.

"Onee-chan has a Student Council meeting today, so... we really will be alone this time. Let’s have a 'rematch' of the other day."

Her large, soulful eyes looked up at me, practically pulling me in. She reached out and took my left hand in both of hers. Her skin was warm—a sharp contrast to Sayuki-san’s perpetually cold hands.

"M-Miharu?"

We’d only just held hands for the first time recently, yet here she was, being so proactive—and at school, where classmates could easily see us. It was so unlike her. Her boldness caught me completely off guard.

Then I realized her small hands were trembling slightly. She was nervous. Knowing that made me feel a little more at ease.

"So... what do you think?" she asked, her voice slightly strained, as if she were under a feverish spell.

Miharu was trying to change.

Maybe it was Sayuki-san’s influence. If it was, then Sayuki-san’s plan was working; history was shifting. We were moving away from the future where we broke up.

That was a good thing.

We had both been too timid for too long. If we were going to take this relationship further, I had a responsibility to meet her halfway. I had to shake off the shadow of 'that girl' once and for all.

"Alright. Let’s go to your place."

"Yay! Okay, let’s go! No time like the present!"

Miharu beamed and linked her arm with mine. She looked up at me with a shy, happy grin.

"This is okay... right?"

"O-of course."

My voice was an octave higher than usual, but I nodded anyway. I could feel the curious stares of the other students pricking at my skin, but as we walked out of the school building, I decided I didn't mind the feeling at all.

My second visit to her house was a little less nerve-wracking than the first.

Today, Miharu led me straight to her room, telling me to wait there while she went to fix some tea.

It really did seem like the two of us were alone in the house; aside from the faint sound of Miharu humming in the kitchen, the place was silent.

I sat cross-legged on a plush pink rug, feeling a bit restless. I’d been in her room before, but my impression of Sayuki-san had been so overpowering that I’d walked away with almost no memory of the actual space.

There was a single bed, a desk, a dresser, and a low table positioned in front of me. The shelves were lined with stuffed animals and small trinkets, including a light-blue randoseru—likely the one she’d used in elementary school. Judging by the pristine sheen on its surface, she still took great care of it. I’d suspected it for a while, but Miharu was definitely the type to treasure her belongings.

"Sorry to keep you waiting!"

She set a tray down on the low table, carrying a tea set and a plate of star-shaped cookies. A lovely, warm aroma drifted toward me.

I’d expected the usual ginger cookies, but today the scent of ginger was particularly sharp, underscored by a rich, toasted fragrance.

Miharu had always been under the mistaken impression that ginger cookies were my favorite. In reality, I found them a bit much—the spiciness tended to overwhelm the sweetness, making them an acquired taste.

But she always looked so happy when she made them that I couldn't bring myself to tell her otherwise.

"Whoa, smells incredible. Are these... fresh out of the oven?"

"Hehe, you noticed?"

"Kind of hard to miss when they smell this good."

"Ehehe. Honestly, I’ve wanted you to try them fresh for a long time. They’re so much crispier—it’s a totally different experience! When you came over last time, we didn't really get a chance to eat, right? So today is my 'rematch.'"

So that was why she’d invited me over.

"Sorry about last time. I got a little too caught up talking with Sayuki-san."

As I bowed my head in apology, Miharu waved her hands frantically in front of her face.

"N-no, it’s fine! Really! Besides, Onee-chan loves astronomy too, so I always figured you two would hit it off."

She said that, but I knew better. No one would be happy if they’d gone through the trouble of baking fresh cookies for their boyfriend, only to have him spend the whole time talking to their sister instead.

"Really, I’m sorry."

"Seriously, if you keep apologizing, I’m gonna feel even worse. If anything, I’m the one who needs to apologize for something."

Miharu sat down beside me. We were so close our shoulders were practically touching. The scent of her shampoo was starting to overpower the spicy aroma of the ginger cookies.

This was another bold move—a level of proactive intimacy I hadn't seen from her before. It made my heart skip a beat.

"What do you have to apologize for?" I asked.

"For... keeping the fact that I had a twin sister a secret."

"No, that’s on me. Sayuki-san is basically a celebrity at our school. I was the idiot who didn't notice even though you have the same last name."

Miharu looked down, her bangs casting a shadow over her eyes.

"The truth is... I didn't want you to meet her. I knew you and Onee-chan would get along perfectly. I was scared that if you met, I’d end up being the one left out."

Her shoulders trembled slightly. The sadness and guilt she’d been trying to bury were finally leaking out.

"So... I’m sorry too."

When she finally looked up, her expression was like a cloudy sky filled with anxiety.

But wait... if that was her reason...

"So you were just jealous?"

"I-I mean... I guess you could put it that way."

Miharu’s cheeks turned a deep, burning red at my blunt assessment.

"Then you have nothing to apologize for."

Actually, knowing she’d been worried about something like that sent a tickle of shy happiness through me.

"Geez! I’m trying to be serious here! Why are you smirking?!" she huffed, glaring at me with an embarrassed pout.

"No, it’s just... seeing you get so worked up over something like that, worrying about it and apologizing... I just thought it was, you know... nice."

"Mmuuu..."

Her blush deepened as her pout turned into a full-on huff.

I’d wanted to say she was "cute," but my "Boyfriend Level" wasn't nearly high enough to say something that embarrassing to her face yet. I’d have to grind some more experience points before I could manage that.

As she softened up, we sipped our tea and munched on the warm cookies.

"Have you ever gone camping before, Miharu?"

The conversation naturally drifted toward the Geminids observation camp coming up in two weeks.

"Hmm. My dad and Onee-chan both love camping, so we’ve been all over the place. But those two usually handled all the heavy lifting like pitching the tents, so I don't have much actual experience."

"Huh. I didn't take Sayuki-san for the camping type. I figured she’d hate getting her hands dirty."

"It might be surprising, but back then, Onee-chan was the one dragging the whole family along. She was such a fast learner, too. Before Dad could even teach her, she already knew how to set up the tents and prep the barbecue. Dad was always puzzled about where she could have learned it all."

Classic Second-Loop Miharu. She’d probably been tagging along on her dad’s hobbies since the first loop, so she was already a pro.

What caught my attention, though, was the fact that Sayuki-san had been to so many different campsites. Maybe...

"...Hey, when you were in elementary school, did you ever participate in one of those star-gazing events organized by a campsite? There were usually about twenty kids, and someone would explain the summer constellations. That was actually how I got into astronomy. I was wondering if Sayuki-san was there too?"

Miharu furrowed her brow in thought. "Hmm, I don't think she ever did anything like that. Onee-chan always preferred looking up at the sky by herself rather than doing it with a group."

"...I see."

To be honest, I still had a lingering suspicion that 'that girl' might have been Sayuki-san, but if Miharu said she wasn't there, she probably wasn't. You need a car to get to those remote campsites; no matter how much of a "second-loop" pro she was, Sayuki-san couldn't have gone there alone as an elementary schooler.

"Anyway, even though we went to all those places, I was always just trailing along behind Onee-chan. I might not be very useful at the camp... sorry," Miharu said, looking dejected again.

"We don't really start the main observation until 7:00 PM, so we’ll have plenty of time. We can just take it slow. Besides, you’re a great cook. I’m sure you’ll get to show off those skills."

I tried to cheer her up, but she only gave me a wry smile.

"You can't really do fancy cooking at a campsite. It’s mostly just barbecue, right? Not much room for 'skills' there."

"Fair point. It is mostly just grilling."

"Yeah. A Miharu who can't cook is just a decorative paperweight."

She slumped.

"Don't sell yourself short. You’re fast, right? If we forget something, we have a specialist who can dash to the store in record time."

"Oh, true! Hehe!" She puffed out her chest with pride for a second before her eyes snapped wide. "Wait, I’m just the errand girl!"

"Took you long enough to notice."

"Hey! Ryuuichi-kun, you’re mean!"

Miharu started playfully thumping her fists against my chest. It didn't hurt, obviously. It had less impact than a hamster's love-bite.

Usually, this was as far as her playfulness went.

"Mmu. No effect? Then try this!"

But lately, Miharu had been getting bolder. She unclenched her fists and lunged for my ribs.

It was a total sneak attack.

"W-wait! Stop! That’s—! K-haha!"

"No escaping!"

Her fingers danced across my ribs and back, each digit moving with a mind of its own.

"S-stop! Seriously, quit it!"

We scuffled and tangled together on the rug until, before I knew it, I was flat on my back with Miharu pinned on top of me.

"..."

Our eyes locked.

She was so close I couldn't see anything but her face. Her cheeks were flushed a brilliant red, her eyes were moist, and her lips looked soft and full. I could hear the sound of her breath hitching through her slightly parted mouth.

A feeling—different from the awe I felt looking at the stars, but just as beautiful—pierced through my chest.

Miharu was being proactive.

Shouldn't I meet her halfway?

Miharu was the reason the Astronomy Club still existed. She was the reason our observation events were so lively. I couldn't thank her enough.

If this was what she wanted...

I felt a ghost of a sensation on my left cheek—the lingering heat of the kiss 'that girl' had left behind.

But this time, it was different. This would be a real kiss.

Miharu wasn't a substitute for 'that girl.' I had to face her properly.

With trembling hands, I gripped her shoulders and began to slowly close the distance...

"T-T-T-TIME OUT!"

Fwump!

My vision was suddenly engulfed in white. It took a few seconds for me to realize a pillow had been shoved into my face. It was a high-end, bouncy pillow that smelled faintly of laundry.

When had she grabbed that off the bed?!

"S-sorry! I... I just wasn't properly warmed up yet!"

"R-right. Me neither. Sorry for rushing things."

"One more time! Just let me try it one more time! Like... a 'Take Two'!"

We decided to reset.

Miharu hopped off me and sat in a formal seiza position a short distance away. She produced a stick of lip balm from somewhere and started feverishly applying it to her lips.

I sat up and mirrored her position, facing her in seiza.

We both froze like statues. The atmosphere felt less like a romantic moment and more like the final match of a national Shogi tournament.

One second, ten seconds... the silence stretched on, becoming heavier by the moment.

Before I could be completely buried by the awkwardness, I forced myself to speak.

"Hey, can I say something?"

"W-what?"

"We really shouldn't have reset. It would have been way better to just go with the flow earlier. Doing it like this... where it feels like we’re about to start a formal duel... it’s incredibly embarrassing."

"Uugh! Don't say it! I was thinking the exact same thing!"

Miharu clutched her head in her hands.

"But I’m not a sprinter with high explosive power! I’m a long-distance runner who needs to prepare! I overthink things!"

"I... think I get what you mean. Sort of."

"So sorry, but... let me practice!"

"Practice? How?"

"Through the pillow!"

With that, Miharu held up the expensive pillow she’d chucked at me earlier, positioning it between our faces.

The pillow was large enough to completely hide her head; from my perspective, it looked like Miharu’s neck had sprouted a giant pillow-blossom.

"Let’s practice with this."

Was I really about to make out with a "Pillow-Man"? I mean, it did take the edge off the nerves since we couldn't see each other's faces.

"Alright. Here I come."

"Okay! Hit me with your best shot!"

Why is she acting like this is a sports anime?

Anyway, I slowly leaned my face toward the pillow. I couldn't see her, but I assumed Miharu was leaning in from the other side too.

The white expanse of the pillow grew until it filled my entire field of vision. When the tip of my nose brushed against the fabric, I felt a brief moment of hesitation, but I steeled my resolve and pressed my face into it.

"Mmgh."

My vision was now completely buried in white. My whole face was wrapped in the cool, silk-like fabric.

Wait. If this is the pillow she uses every night, isn't burying my face in it actually kind of creepy?

...Yeah, this was definitely embarrassing. It was basically like I was sniffing her pillow.

The realization made me stop breathing.

Right now, through the barrier of the pillow, our faces were inches apart.

My eyes were blocked, and the sensation was mostly absorbed by the cushion, but I could feel her presence right in front of me.

To think Miharu’s face was just on the other side of this white void... the tension was actually starting to feel real.

I don't know how long we stayed like that. Maybe it was just a few seconds, maybe a full minute.

Eventually, I pulled back. My head had left a noticeable indentation in the pillow.

"Phew..."

Miharu pulled back at the same time.

The pillow that had separated us was slowly lowered, and Miharu’s face emerged like a rising sun. Her breath was coming in short, ragged gasps, and her cheeks were burning.

"...So. How was the practice?" I asked.

Miharu nodded timidly. "Yeah. I think my 'image training' is complete."

"T-then... for real this time. Here I come."

Miharu’s shoulders jumped, but this time she didn't look away. She stared straight into my eyes.

"O-okay."

Once again, our faces drew closer.

There was no pillow between us this time.

That one tiny difference made the tension skyrocket.

I could see every detail of her face: her long, slightly curled lashes; her large, moist eyes; the cute tip of her nose; her cheeks, now redder than a ripe apple; and her pale pink lips, trembling with nerves.

I moved closer, inch by inch.

My heart was pounding so hard I thought it might burst. It felt as fragile as a paper goldfish scoop that had been left in the water too long—it could tear at any moment.

I pushed through my internal conflict, closing the final gap.

Almost there.

Then, from the hallway, I heard the click of the front door opening. Sayuki-san’s voice followed immediately after.

"I’m home! Miharu, you here? I see Ryuuichi-kun’s shoes—is he over?"

In a flash, Miharu’s face—which had been right in front of mine—vanished.

"Uugh! Onee-chan! Your timing is terrible!" Miharu puffed out her cheeks and glared at the bedroom door.

"So... uh... what now?"

The mood was completely dead, and the awkwardness was unbearable. Miharu turned back to me with a disappointed smile.

"Let’s... save it for next time. For now, we better look like we’re studying."

Chased by the sound of Sayuki-san’s approaching footsteps, we scrambled to pull textbooks and notebooks out of our bags and scatter them across the low table.

Just as our "crime scene" was staged, the door opened and Sayuki-san stepped in.

"Oh, you are here. Welcome, Ryuuichi-kun."

"H-hey. Sorry for the intrusion."

"..."

Sayuki-san’s eyes darted between Miharu and me, searching for clues. The silence was terrifying. I hoped she hadn't realized we were seconds away from kissing, but with her, I had the feeling she saw everything.

"Have you two been studying this whole time?"

"Y-yeah! Final exams are coming up, after all. If I don't get good grades, it’ll affect my club activities," Miharu blurted out.

"Oh? How studious of you, Miharu. Here, let Onee-chan take a look."

Sayuki-san reached for the notebooks we’d hurriedly spread out and began flipping through them.

"This is a math notebook, isn't it? Then why do you have an English textbook open?"

Crap. In our rush, we hadn't bothered to check for consistency.

"I’m trying to study two subjects at once! For... maximum efficiency!" Miharu countered instantly.

I knew it was a pathetic excuse, but I nodded along like one of those bobblehead dolls.

"...Hmm."

Sayuki-san narrowed her eyes meaningfully.

She definitely knows.

But she didn't push it. Instead, she just shook her head with an exasperated sigh.

"I think that’s actually the opposite of efficient. If you want to study for the finals, I’ll help you. You know my predictions for the test questions are usually spot-on, don't you, Miharu?"

"I mean... yeah, I know."

Sayuki-san was on her second loop; she’d already taken these tests once. She probably knew exactly what would be on them.

"Right? Leave it to your Onee-chan. If you study the areas I tell you to, you’ll get a high score easily."

With that, Sayuki-san squeezed herself onto the rug, sitting right between Miharu and me.

The fresh, citrusy scent of Miharu’s shampoo was instantly overwritten by Sayuki-san’s lavender fragrance. The contact of her shoulder against mine felt... softer than Miharu’s had. It felt more distinctly feminine, and my whole body went rigid.

"H-hey! Onee-chan! Don't just barge in!"

"How am I supposed to help you both study if I don't sit between you?"

"You could sit across from us!"

"Then the textbooks would be upside down. It’s too hard to teach that way."

Sayuki-san fired back at Miharu’s protests, looking like she was actually enjoying the argument.

"Look, even Ryuuichi-kun looks uncomfortable! Get back!"

"Oh? Is that true, Ryuuichi-kun?"

The pressure from both of them was too much. My gaze darted between the two sisters until I spotted salvation in the form of the setting sun shining through the window.

"S-sorry, but I should probably head home. The weather is supposed to be clear tonight, so I want to do some astrophotography. You know... for the comet! I need to keep searching for it!"

I didn't actually have any such plans.

I shoveled my books back into my bag and stood up. Both girls looked dissatisfied, but neither tried to stop me.

They walked me to the front door.

"See you later, Ryuuichi-kun."

I turned back to see Miharu, her cheeks still pink, giving me a small wave.

...Come to think of it, we really were just seconds away from kissing.

Uugh, the awkwardness. How am I supposed to face her tomorrow? Can we even talk normally after that?

I was so lost in thought I couldn't even meet Miharu’s eyes. She seemed to feel the same way, as her gaze was firmly fixed on my feet.

"...Yeah. See you at school."

I managed to choke out those few words before practically bolting out the door.

Preparations for the observation event tomorrow were perfect.

I’d locked in the schedules for Inou-sensei and the two members, prepped all the equipment we needed to bring from school, confirmed the campsite reservation, and mapped out the route. We were ready to go.

Except for one thing. One massive, glaring failure in my preparations.

The birthday present for Miharu.

I’d originally planned to give her the giant teddy bear she’d been cooing over, but after Sayuki-san’s brutal critique, I’d been searching for a replacement. And I’d come up with absolutely nothing.

I had to find the perfect gift today. Something wonderful enough to make up for all the time I’d wasted.

After school that day, I finished the final check of the club equipment. Driven by a mix of panic and a sense of duty, I headed toward the school entrance.

As I was walking out, lost in thought about what to buy, I ran right into Miharu. She was wearing her track-and-field uniform.

We both froze for a second.

"Oh... R-Ryuuichi-kun. Heading home? Good work today. I’m really looking forward to the camp tomorrow."

Her smile was a little strained. Ever since the near-kiss, we’d both been acting incredibly awkward around each other.

It wasn't like we were avoiding each other; it was more of a shy, self-conscious distance. It wasn't a bad feeling, per se, but it was definitely new.

However, right now, I had a different reason for finding it hard to look her in the eye.

"Yeah. You heading to track practice?" I asked.

In her uniform, she looked ready for the track. Her legs, visible beneath her short pants, were long, toned, and looked healthy and tan. I’d given the Astronomy Club the day off today to rest up for tomorrow.

"U-huh! I’m so excited for tomorrow that I’ve got energy to burn! I might even set a new personal best today!"

To demonstrate this overflow of energy, she started doing high-knees on the spot.

Her reaction felt a little exaggerated. Miharu was probably still trying to figure out how to act around me, too. But the fact that she was so conscious of me made me a little happy.

Which made me feel even more pathetic for not having her surprise gift ready yet.

"As the President of the Astronomy Club, I’m glad to hear you’re so excited. I’m looking forward to that barbecue you promised."

"I... hope I can live up to the expectations. I’ll do my best!"

Just then, someone called out to her from the field.

"Heeeey, Miharu! Hurry up and get over here!" A group of girls in track uniforms were waving her over.

"Sorry, Ryuuichi-kun! I gotta go!"

"No, I’m the one who stopped you. Good luck with practice. Don't overdo it."

"Thanks! See ya!"

I watched her run off toward the other girls.

My mind drifted back to late April, when I’d first joined the Astronomy Club.

At the time, the only members were me, the third-year President, and a ghost member who only existed on paper to keep the club from being disbanded.

One day after school, I was on the roof, prepping for an observation. The President was running late, so I was working alone in silence.

The roof offered a perfect view of the school grounds. While waiting for the sun to go down, I used to kill time by watching the other students.

The sports clubs were all in full swing. The soccer team was on the main field, the tennis team was in the corner... and the track team was running laps around the oval, over and over again.

"They’re like satellites," I’d muttered to myself on the empty roof, my voice immediately swallowed by the wind.

To my eyes, the long-distance runners circling the track looked like artificial satellites that could never quite break free from the Earth's gravity.

7.9 kilometers per second. That’s First Cosmic Velocity—the speed required to maintain a circular orbit around the Earth. These runners were trapped by that velocity.

Even after launching themselves into space, these pitiful artificial stars could never truly leave the Earth behind. I hated satellites for that reason.

Part of it was because their light interfered with astrophotography. But mostly, it was because they reminded me too much of us.

Everyone is bound by gravity, circling the same spot forever. We tell ourselves we’re moving forward, but in reality, we’re just trapped by the gravity of "common sense," spinning in circles.

Tradition, public opinion, peer pressure... we want to break free from the gravity the world creates, but we never can. I was just as pathetic as the rest of them.

I was still being pulled along by the gravity of 'that girl' in my memories. I knew it was pathetic, but I couldn't help it.

To reach "infinite distance"—the speed required to truly break free from Earth's pull—you need Second Cosmic Velocity.

Second Cosmic Velocity is only about 1.41 times faster than the first. Just by pushing yourself that little bit further, you can shake off your shackles and go somewhere—anywhere—else.

But it’s not that simple. Even aerospace engineering struggles with that barrier.

The track runners in my vision were the same.

As I watched from the roof, I saw one runner suddenly swerve off the track. I figured she’d hit her limit and dropped out of the lead pack.

But she didn't stop to rest. She actually sped up, racing toward a runner at the very back of the pack who was half a lap behind.

She tapped the girl on the shoulder, urging her to stop. She seemed to be telling her not to push herself too hard.

The lead runner threw the other girl’s arm over her shoulder and led her off the track toward the shade. A coach came running over, looking panicked.

If that girl had kept running, she might have collapsed from heatstroke or dehydration. While everyone else was focused on their laps, she was the only one who noticed something was wrong. She was the only one who broke her orbit and raced to help.

In that moment, she was the only one who had reached Second Cosmic Velocity.

Looking down from my high-and-mighty perch on the roof, I had no way of knowing that girl would eventually become the savior of the Astronomy Club. I certainly never imagined she’d become my girlfriend.

Miharu hadn't changed at all since then. She was always looking out for others. And now, she was looking at me.

I wanted to thank her. I wanted to reward her for all her hard work.

That was why I needed a gift that would make her truly happy.

As if sensing my resolve, my phone vibrated, pulling me back to the present. The name on the screen was exactly who I expected.

The moment I answered, her voice tickled my ear.

"So? Have you decided on a present yet?"

She sounded like she already knew the answer.

"...I’m sorry. Could you help me out?"

"Fufu. Of course."

Sayuki-san’s voice sounded like that of an angel... or perhaps a devil.

“Well? What do you think?”

Opening the fitting room curtain, Sayuki-san stood there, perfectly pulling off a grey high-neck sweater. She posed with a hand on her hip like a professional fashion model. The sight of her—radiating such mature, sophisticated allure—sent my heart into a frantic, unrelenting rhythm.

“...It looks great on you. But,” I started, trying to find my voice, “weren’t we supposed to be picking out a gift for Miharu?”

“Oh, sorry. But isn’t it easier to choose clothes when you see how they actually look on a person? Since I’m her twin sister, I thought I’d make a good reference.”

“If you were identical in every way, sure, that might work. But in your case, Sayuki-san... you and Miharu are just too different.”

The sweater clung to her, emphasizing the suggestive, lustrous curves of her body. Even if Miharu wore the exact same thing, it wouldn’t look like this. Their silhouettes were simply on different levels.

“Hmm. You think so? Well, why don’t we think about it after I try on maybe two more outfits?”

“You just want to play dress-up, don’t you?”

When I responded with an exasperated sigh, Sayuki-san stuck out her tongue playfully. “Caught me, did you?” she giggled.

“Well, I suppose it can’t be helped. Shall we try hats or gloves next? Body type doesn't really matter for those. I’ll change back in a second, so could you wait for me?”

The curtain slid shut once more, swaying slightly as it caught the draft of my heavy sigh.

I had been dragged to a nearby department store by Sayuki-san. Our first stop had been the cosmetics floor—an unknown sanctuary where I was forced to navigate the bewildering world of "budget brands" and "high-end counters."

“I think a daily-use sunscreen might be nice, don’t you? This one has moisturizing ingredients and is quite a steal, while this other one is waterproof—perfect for when she’s sweating during track and field practice.”

Sayuki-san picked up one product after another, offering detailed commentary on each.

“She’s always worried about smelling like sweat after club activities, so maybe a body mist? A citrus fragrance like this is light and easy to wear. Or... maybe we should just pick based on how cute the packaging is rather than what’s inside.”

After checking out everything there, I was pulled into a women’s fashion boutique to look at the new winter arrivals. Though, before I knew it, the trip had devolved into a personal fashion show for Sayuki-san.

Between the makeup and the clothes, the sheer variety of gifts for girls was dizzying, and the prices were enough to make my head spin. If I’d been here alone, I never would have been able to choose anything.

“Sayuki-san, are you almost ready to go?” I called out to the tightly drawn curtain.

“Geez, don't rush me, Ryuuichi-kun. It takes time for a girl to change, you know?” came her huffy, pouting reply.

I wished she’d consider the feelings of a guy left standing all alone in the women's fashion section. The place was packed with female clerks and shoppers; I felt their eyes on me, and the self-consciousness was becoming unbearable.

I guess I’ll just check my phone memos and think about the gift while I wait, I thought.

Just then—

“Excuse me. I’m Kunitomo. I had a reservation?”

“Yes, we’ve been expecting you. Right this way, please.”

A familiar voice was speaking to one of the clerks.

I instinctively glanced toward the sound. There stood Kunitomo in her school uniform, being led by the staff.

“This is the item you ordered, correct?”

The clerk emerged from the back and unfurled a red muffler for Kunitomo to see.

“Ah, yes. That’s the one.”

That idiot. It looked like Kunitomo had come to pick up the birthday present she’d reserved for Miharu. What a stroke of cosmic bad luck! If she’d just gone to any other store, we wouldn’t have crossed paths.

If I stayed standing here in front of the fitting rooms, I was dead. If Kunitomo spotted me, she’d obviously ask who I was with, and there would be no way to keep Sayuki-san’s presence a secret.

I looked around frantically for a place to hide. But my suspicious, shifty movements backfired—Kunitomo seemed to sense someone's presence and started to turn her head toward me.

It was checkmate. But a split second before she saw me—

“Get in!”

A hand reached out from the fitting room and yanked me inside.

The curtain snapped shut instantly, shielding me from Kunitomo’s gaze in the nick of time.

“Th-thank you. You saved m—”

The words died in my throat.

What met my eyes was skin as white as fresh-fallen snow. It reflected the bright fitting room lights, glowing with a brilliant radiance.

Upon that dazzling snowfield sat two large mounds, their peaks covered in violet lace. It took my brain a few agonizing seconds to realize I was staring directly at Sayuki-san’s ample chest, constrained tightly within the cups of her bra.

“Y-you’re in your underwear!”

“I didn't have a choice, did I? I was in the middle of changing.”

“How are you so calm about this?! Normally, a person would try to cover up!”

Staring was obviously out of the question, so I wrenched my gaze toward the far corner of the room.

However, because of the full-length mirror hanging on the wall, I ended up seeing the reflection of Sayuki-san’s beautiful back, the elegant straps of the bra, and even the hooks of the rear fastener.

Wait. The more I try to look away, am I just ending up with a three-hundred-and-sixty-degree view of her in her lingerie?

“...I don't really mind if it's you, Ryuuichi-kun. If anything, I want you to look more.”

The fitting room was barely large enough for one person to stand and change. By necessity, we were standing so close that our shoulders were brushing. If I moved even a fraction of an inch, I’d be able to feel the direct softness of her body.

N-no. Bad. Kunitomo is right outside. Don't think about anything weird.

“What’s wrong? You’re interested too, aren’t you, Ryuuichi-kun? You can sear the image into your memory if you want.”

Sayuki-san let a poised smile play on her lips as she placed both hands beneath her breasts, slowly lifting them.

Despite being firmly held by the bra, they changed shape as if they were melting, looking as though they might spill over the lace cups and the straining straps at any moment.

“It’s actually quite a lot of work to maintain these, you know? I have to train my pectoral and back muscles just to support all this weight. Plus, the cleavage and the underbust get sweaty easily, so I have to take care of the skin every day to make sure I don't get a heat rash.”

“......”

She was sharing a woman’s private struggles with me, but none of it was registering. My brain had hit its processing limit.

“But if it makes you happy, Ryuuichi-kun, it’s no trouble at all. Besides... it’s not like you’ve only looked at them before. You’ve touched them, and licked them...”

Wait, my future self and her... we’ve gone that far?!

Inside the cramped fitting room, my own ragged breath and the heat rising from Sayuki-san’s skin had nowhere to go, tangling together in the air.

Just as the words died between us, a voice drifted in from outside the curtain.

“How would you like this item wrapped?”

It was the clerk, followed by Kunitomo’s response.

“Um, it’s a birthday present for a friend, so please use some cute wrapping paper. Oh, but she’s probably going to get a present from her boyfriend, too, so try to make mine not stand out too much, okay?”

“Certainly. Please wait just a moment.”

I could tell the clerk was responding with a professional smile to the specific request.

She’s putting that much thought into Miharu’s gift? She’s even worried about the balance between her gift and the boyfriend’s...

Compared to her... what the hell am I doing in here?

The feverish heat in my consciousness cooled instantly.

“S-Sayuki-san, I’m sorry. Could you please put your clothes back on?”

Sayuki-san gave a lonely little smile and slid her arms into the sleeves of the school blouse hanging on the rack.

“Listen, Ryuuichi-kun. Being serious is fine, but being too late of a bloomer isn't good either. At this rate, just like what I experienced, the two of you might end up heading toward a future where you break up.”

Sayuki-san broke the awkward silence that had settled between us.

“Th-that’s not going to happen!”

“Are you sure? What if Miharu comes onto you the way I just did?”

“...To be honest, I can’t even imagine Miharu acting like that.”

“But it’s a possibility. I know exactly what happens once her switch is flipped.”

“Because you’re the 'second-loop' Miharu?”

“Exactly. ...That’s why you need to practice various things with me, so you’re ready for whatever happens.”

In that instant, Sayuki-san’s face was suddenly right in front of mine.

“P-practice...?”

“For example... a kiss.”

Sayuki-san pressed her index finger against her own lips.

She stared at me with such deadly earnestness that I found myself frozen, like a frog in the gaze of a snake.

Outside the fitting room, I could still hear the exchange between Kunitomo and the clerk. Apparently, she was agonizing over whether the ribbon should be red or blue. Just pick one already!

As long as Kunitomo was in the store, we couldn't leave this room.

“What are you talking about? I can't do that.”

Perhaps seeing my inner conflict, Sayuki-san let out an exasperated sigh.

“Sigh... I guess it can’t be helped. Then, if we do it the same way Miharu does, that’s fine, right?”

The same way?

Sayuki-san rummaged through the bag she’d left in the corner of the room and pulled out an English vocabulary book. From inside, she drew out a translucent red sheet—the kind of bookmark-style filter used to hide answers written in red ink.

Sayuki-san covered her mouth with that thin sheet. I say "covered," but since it was translucent, her lower face just took on a reddish tint; I could still see everything perfectly.

“Mmph.”

Sayuki-san was staring at me. She seemed to be demanding something.

“What is it?”

“Aren't you going to kiss me?”

“Huh?”

“You practiced with Miharu through a pillow, didn't you?”

I knew it. She knew about what happened the other day. I guess something similar had happened in the first loop, too.

“See? There’s a red sheet in between us, so there shouldn’t be a problem.”

“W-wait! With something that thin?! The thickness is completely different!”

“But if it’s too thick, it’s not good practice. This is the perfect thickness. Of course, if you have something thinner, Ryuuichi-kun, I don't mind using that instead.”

“I-I don’t! And I think this is too thin.”

“But if doing it directly is impossible, this is the only way, isn't it?”

...If a third party heard this conversation, I was certain they’d get a disastrously wrong impression.

“B-but...”

“...Heeere.”

With that, Sayuki-san lightly puckered her lips through the red sheet. Seen through the translucent red film, her lips looked as if they were painted with lipstick, giving her an incredibly mature appearance.

Those red lips naturally drew my gaze, like a single rose blooming in a garden.

Like an insect lured by nectar, I found myself guided toward her face, toward her lips.

Her eyelashes were thick and long even without mascara, and the large eyes beneath them slowly began to flutter shut.

This was completely different from the time I practiced with Miharu and the pillow. Back then, the pillow had hidden Miharu’s face, but now, most of Sayuki-san’s face was right there in my field of vision. Besides, the red sheet was translucent; it was basically the same as not hiding anything at all. Was this really okay?

In the split second I hesitated, Sayuki-san closed the remaining distance all at once.

What I felt on my lips was the sensation of thin plastic. But beneath it, I could faintly sense Sayuki-san’s warmth.

It felt more immoral, more like I was committing a taboo, than a direct kiss ever could have.

“Nnh.”

The sweet sound that escaped Sayuki-san’s lips began to melt away my guilt.

How long did we stay like that? It felt like an instant, yet also like an eternity. The only thing I knew for certain was that this moment had been burned into my very soul.

Sayuki-san’s face slowly pulled away.

I shouldn't feel reluctant to let go. I knew that, yet I couldn't deny the existence of that desire in the corner of my mind.

The sensation of "that girl’s" lips, which should have been branded into my left cheek, had faded so much I could no longer recall it.

As Sayuki-san moved to put the red sheet back into her vocabulary book, I saw it—the lip cream she had been wearing had left a red lip print on the surface. It was the proof that we had pressed our lips together across that thin barrier.

“Was that good practice?”

Sayuki-san narrowed her eyes with a bewitching smile.

“T-to be honest, it happened before I even knew what was going on, so I don't feel like I can apply this experience to anything.”

“Hehe, you’re so honest. If you want, do you want to try one more time?”

“I-I’ve had enough!”

Thinking she might actually do it again if I stayed there, I hurried to the curtain and listened for any sounds outside.

I couldn’t hear Kunitomo’s voice. I peeked my head out and looked around.

“Look, Sayuki-san. It seems Kunitomo is gone. Let’s get out of here, quick.”

“Oh dear, I’ve been rejected.”

Sayuki-san gave a disappointed chuckle and slung her bag over her shoulder.

５

“Well, thanks for today. I’m glad we found something good.”

“Yeah, I’m glad you were here to help, Sayuki-san. I don't really understand presents for girls. Even if I’d asked Kunitomo, she probably wouldn't have been as knowledgeable as you.”

In the end, we’d decided on a pair of boa-lined gloves. They were a necessity for future outdoor stargazing sessions and practical for daily use as well.

We left the department store and headed toward the nearest station. It was that time of day when the sky was a gradient between evening and night, and the area was crowded with swarms of people coming and going.

“So, do you feel a bit more confident now?”

Walking beside me, Sayuki-san laughed as she playfully bumped her shoulder against mine.

...She was talking about the kiss.

“I’ll... I’ll do my best.”

“Hehe. If you ever want to practice before the real thing, just let me know. Or, you know, you could just make me the 'real thing' instead.”

My eyes were drawn to her lips as she spun those seductive words, her breath turning white in the cold air.

“I-I’m fine, really!”

I sped up my pace, shaking off Sayuki-san’s temptation.

Just then, I spotted a familiar short-haired silhouette directly ahead of us.

“Wait, that’s Kunitomo, isn’t it?”

“...Yes.”

There was no mistake. She was wearing the same uniform, and more importantly, the paper bag she was clutching carefully to her chest was from the same boutique we’d just left. I was carrying an identical bag containing the gloves for Miharu.

“I don't think she’ll notice us with all these people around, but maybe we should keep our distance?”

Sayuki-san didn't seem to hear my suggestion; she was staring intently at Kunitomo walking ahead.

“...Yuria-chan looks like she’s not feeling well.”

Prompted by her words, I looked more closely.

Now that she mentioned it, Kunitomo had been coughing into her hand for a while now, and her face looked a bit flushed. Despite being a track sprinter, her gait was unsteady; she occasionally stumbled into passersby and bowed in apology.

“You’re right. I'm surprised you noticed. She seemed perfectly normal at school.”

“That girl tends to endure things so she doesn't worry the people around her. Especially with the training camp tomorrow. She’s probably been feeling bad for a while but was forcing herself to act energetic.”

Kunitomo definitely had that side to her.

“You seem to know Kunitomo very well.”

“Of course I do. Yuria-chan was my best friend... once.”

As she whispered the last word, Sayuki-san looked incredibly lonely—her expression pained.

As if to say that wasn't the case anymore.

Come to think of it, while Miharu called her "Yuria" without any honorifics, Sayuki-san used "-chan." It suggested a significant distance between them.

Right. To Sayuki-san, Kunitomo is no longer her best friend.

Kunitomo had said it before—that Sayuki-san was like someone living above the clouds. Meaning, she was someone she could no longer stand beside...

An unexpected silence fell between us, and our footsteps grew heavy.

In that time, Kunitomo’s figure was quickly swallowed by the crowd, vanishing from our sight.

Then, I felt a soft, cold sensation against my hand. It was Sayuki-san’s hand.

She had reached out to make sure we didn't get separated in the throng. But her hand was trembling slightly. She looked like a child who was terrified of getting lost.

“...Hey, Ryuuichi-kun. Please... stay by my side from now on.”

Sayuki-san turned a transparent gaze toward me.

In the depths of her eyes, I felt like I saw a bottomless sense of loneliness, one powerful enough to swallow me whole. I wondered if this was her true feelings—the ones she had kept hidden beneath that bewitching smile all this time.

“Sorry for saying something strange.”

Sayuki-san’s hand slowly slipped away from mine.

“Shall we head our separate ways here for today? Make sure you stay warm tonight so you don't catch a cold like Yuria-chan, okay? ...Though, if you’d like, I could hop into bed with you and warm you up myself.”

“I-I’ll pass!”

The usual teasing smile had returned, and I felt a small wave of relief.

“Hehe, even the tips of your ears are bright red. What were you imagining? So cute.”

Sayuki-san’s hand reached out and began to playfully pinch and poke my earlobe. The heat from my embarrassed ears was stolen away by her fingers, which were as chilly as a snow woman’s.

“H-hey, stop that.”

“Oh? I thought you liked having this part played with, Ryuuichi-kun? You know, you’ve let me bite it many times in bed.”

What the hell is my future self doing?!

Because she said that, I couldn't help but visualize the image of Sayuki-san’s plump lips nibbling on my earlobe.

“K-keep the teasing to a minimum! Think about where we are!”

I hurriedly brushed Sayuki-san’s hand away.

“Oh dear, what a shame. I quite like the feel of your earlobes, Ryuuichi-kun.”

She had completely returned to her usual self. I wasn't sure if I should be happy or disappointed.

After she finished laughing, Sayuki-san raised the hand she’d been using to cover her mouth and gave a little wave.

“Well, I’ve had my fun, so I should probably head home. See you, Ryuuichi-kun. See you tomorrow.”

“Yeah. Thanks for today.”

As I bowed to her retreating back, a question suddenly flickered in my mind.

See you tomorrow?

Tomorrow was Saturday, so there was no school. There was the Astronomy Club training camp, but the participants were just the three club members—including myself—and our advisor, Inou-sensei. Naturally, there shouldn't be any chance to see Sayuki-san.

And yet, her parting greeting sounded as if our meeting tomorrow was already a settled matter.

By the time I looked up, she was already gone, and the chance to resolve my confusion was lost.

Sayuki-san probably just made a mistake, I thought.

Even so, I had a certain feeling of conviction.

It wasn't a mistake.

I had a feeling I would definitely be seeing Sayuki-san tomorrow.