That night, the first night of my sister-run total-surveillance private utopia, I—Ayabe Yuuma—couldn’t sleep at all.

The smartphone by my pillow felt like the gatekeeper of hell itself.

GPS location tracking… at its core, it was no different from what Hinomiya Akane did back in Kumamoto.

But this time, the one doing it was my sister—someone living under the same roof, someone I couldn’t legally cut ties with, the closest kind of stranger imaginable.

In terms of having no escape, this despair was on a completely different level from anything in my past.

“…I’m doomed.”

The next morning. When I opened the living room door feeling gloomy, I found Mirei already in her uniform at the table, expressionlessly biting into a piece of toast.

“Good morning, Onii-chan.”

Her voice was flat. Her eyes held no trace of emotion—only a cold gleam, like that of a researcher observing a test subject.

I couldn’t even bring myself to bring up last night’s message. I just gave a vague nod and sat down in my seat.

In the awkward silence, the sound of a butter knife scraping the plate echoed unnaturally loud.

The moment I so much as got excited over Yukishiro Miru, this sister had grasped it perfectly. Did that mean this surveillance network could even pick up the slightest shifts in my emotions? Could she actually be reading my thoughts…?

“…Onii-chan, why are you smirking? It’s gross.”

“Eh?”

The word slipped out before I could stop it. I wasn’t grinning. If anything, I’d been trembling in fear.

“I know exactly what’s going on. You were thinking about Yukishiro-san, weren’t you? You’ve always been easy to read, Onii-chan.”

“……!”

I was completely seen through.

Did she share my memories from Kumamoto? Or did she simply understand me, as a little sister, on some fundamental, instinctive level?

Either way, the sharpness of it peeled away the thin skin I called privacy with terrifying ease.

I shoved the toast down my throat and bolted out of the house—feeling Mirei’s gaze stabbing into my back.

“I will… become my Solid Self… absolutely…”

As I walked through the frozen winter streets, I muttered it like a spell. This time for sure—I would stand on this land in my own shape, not fitting into anyone else’s vessel.

With that firm, unwavering determination, I opened the classroom door—and at that very moment:

“Ah, Yuuma-kun! Morning!”

The sun was there.

Bathed in the morning light pouring through the window, Yukishiro Miru waved at me with a bright, carefree smile. Her shimmering hair caught the light, forming something like a halo.

I knew it. This smile was the gravitational pull of “fate” leading me straight to ruin. But I had no method to avoid that light.

The instant I saw that brilliance, my iron will nearly melted into sherbet.

“Fifth period is our ski class! I’m very excited!”

“A-aa…”

Stop. Don’t look at me with those innocent eyes. I’m a Liquid Self. If you smile like that, I’ll spill right into your smile-shaped vessel any second now.

“I… I’m going to practice alone today.”

Somehow, as I sat down, I managed to squeeze that much out. My voice might’ve been shaking a little.

“Ehh, why? Yesterday, I said I’d teach you, remember?”

“We didn’t make a promise. You just declared it on your own.”

“Let’s not sweat over small details!”

Miru leaned in close. A faint citrusy shampoo scent brushed against my nose. Too close. Both physically and mentally. Does this girl not understand the concept of personal space?

“I’m doing training… to become my Solid Self with my own power. So… don’t interfere.”

Even I knew I was talking nonsense. But this was it—this “training” excuse would let me keep my distance from Miru and show my sister that I was working hard toward becoming my Solid Self. Perfect strategy, right?

I could hear the boys whispering:

“What’s with him? He just turned down Yukishiro-san.”

“And he’s saying weird stuff too.”

“Transfer student privilege? Lucky bastard.”

No, no, you idiots. This is a survival strategy!

But Miru didn’t mind my bizarre behavior at all. On the contrary, she clapped her hands together and smiled even brighter.

“Ohhh, training! That’s great, Yuuma-kun! Hmmm… so does that mean it was actually your awkward way of asking me to teach you one-on-one?”

“Were you even listening!? How did you reach that conclusion!?”

“Then I’ll help with your training! I’ll support you one-on-one until you become your Solid Self! Perfect, right?”

No good. Reason doesn’t work on this sun. Everything I say gets converted into convenient fuel for her.

Ding-dong, ding-dong.

The bell mercilessly signaled the start of the first period. Miru gave me a quick “Okay, see you in fifth period!” and a wink before heading back to her seat.

I collapsed onto my desk.

Classes hadn’t even started yet, and my mental exhaustion was already at its peak.

◇

And then, the fifth period of fate.

We had come to an artificial ski slope on the gentle hillside behind the school. For me, who had only ever swung bamboo blades or ran around the field in Kumamoto, Kyushu, it felt more like another world than just a different culture.

“Okay… I’ll do it…”

I wrapped myself in my ski gear and took up the rental skis and poles, renewing my resolve. Miru was sending glances my way while doing warm-up exercises with the other girls.

From around us came voices like “Hey, look at this, Yukishiro-san, she’s completely locked onto Ayabe!” “She’s already dating him, isn’t she?” “Ugh, I can’t stand this!”

Just watch, all of you—and you too, Yukishiro Miru. My Liquid Self isn’t just a mental weakness. Even my physical abilities will adapt to whatever situation I’m thrown into… or at least, they should.

First, I need to put on the skis.

Hooking my boot’s toe into the binding and stepping down on the heel…

Thunk!

I tried with my right foot first.

Thunk!

…It didn’t click.

Thunk! Thunk!

“Ugh… why is this happening…”

The bindings were as stubborn as a fortress resisting my enlistment, tightly sealed shut.

While I was struggling, the other students had already finished preparing and started skiing.

“Geez, Yuuma-kun! I told you I’d help you!”

Patter-patter, light footsteps approached. No need to turn around. It’s the embodiment of the sun, Yukishiro Miru.

“I can do it myself! This is training!”

“You’re so stubborn, you know. Look—there’s snow packed on the bottom of your boot. You’ve gotta clean it off properly.”

Saying that, Miru naturally crouched in front of me and began tapping the bottom of my boot with her pole’s grip end.

“Wa, hey, I can do it myself!”

“Just let me. Come on, lift up your other foot too.”

Her tone was unyielding. Her movements were surprisingly practiced. The tips of her fingers brushing against my ankle as she cleared snow from my boots felt oddly warm in the cold winter scene.

“Okay, that’s good! Try again now.”

I did as I was told and stepped down on my heel again.

―Click!

This time, with a light click, the boot locked onto the ski.

“…Oh.”

“That’s right? Then your left foot too.”

Miru lifted my left foot again and repeated the same process. Her head was so close to my knee that my heart made an odd sound.

Stop it, my heart. Don’t you get swept away too. If even you turn to liquid, I’ll really just end up as plain old “Ayabe soup.”

Click!

The left foot was successfully attached. For the first time in my life, I stood on snow with both skis on my feet.

“Good! Then let’s go!”

“No, I can do it by myself…”

“It’s fine, let’s do it together! It’s definitely more fun with two people than alone!”

Her smile felt like it came with its own sound effect.

Under that smile, my resolve to “do it alone” melted away like early spring snow—vanishing as it sank into the ground.

“…Why am I like this…”

My sigh fell unheard, swallowed by the dry northern air.

“Kay then, let’s start with the snowplow!

Put the tips of your skis together like this and make a reverse V shape!”

Miru demonstrated effortlessly right before my eyes.

“I-I understand…”

I awkwardly tried to attach the fronts of my skis. But the unfamiliar boards wouldn’t listen, crossing each other and causing me to fall beautifully on the spot.

With a clumsy sound, I buried my face in the snow.

“Ahaha! Yuuma-kun, are you okay?”

A cheerful laugh, light and tinkling like rolling bells, drifted down from above.

Ah, I’m done. I can’t resist this comfort. My plan for a solid self was already facing its greatest crisis right at the start.

Then I noticed the cold, heavy presence of the smartphone in my pocket.

Watching.

My sister is surely now, watching this scene, estimating it from my heart rate and GPS data.

The moment I thought that, something cold ran down my spine. Not the crisp cold of the ski slope—but a sticky, clinging kind of dread.

◇

And after school.

Somehow, I was still on the ski slope.

Alone with Yukishiro Miru.

Classes had long ended, and all the other students had gone home. The sunset dyed the snowfield a crimson hue, stretching our shadows long and long.

“I… was supposed to go home…”

I looked up at the sky, sighing in despair while still wearing my skis.

It was right before PE class ended that Miru said this.

“Yuuma-kun, you could barely slide at all! If you stay like this, the next class is gonna be rough! So—let’s practice after school too! I’ll make sure you can ski perfectly!”

And so.

Of course I refused. I had refused. “Because my sister is waiting,” I listed every possible excuse.

But she tilted her head and said,

“Ehh? But Yuuma-kun, didn’t you just say you were doing ‘training to become your Solid Self’?

Is training something you can give up on that easily? …Or is it that you hate being alone with me that much?”

…I couldn’t even argue.

I’d ended up trapping myself in the ridiculous setting I made up.

“I’m such a weak-willed person… making the same mistake again…”

Wasn’t there a part of me that actually wanted this? A part that wanted to be freed from the pain of struggling alone… A part that wanted to just let myself drift along in this warmth…?

“Yuuma-kun! What’s wrong? You’re better than before, so have more confidence!”

Miru, who had been waiting a bit ahead, turned around and called out to me.

That’s right. After about an hour of training, I’d finally learned how to stop using the plow turn. Miru’s way of teaching was unbelievably good.

“Okay? Loosen your knees and lower your center of gravity!”

A hand was gently placed on my waist from behind, and advice whispered near my ear made my heart’s BPM skyrocket.

“L-like this…?”

“Yes yes! Good job!”

I was praised openly. The experience of being taught something with pure goodwill and then praised… might be the first time I’ve ever had it.

That’s why…

I can’t do it.

If I get used to this warmth, I’ll never be able to return to my “solid self” again.

I pushed off down the slope with all the determination I had. I would stop—this time, with a perfect plow turn, right in front of Miru, clean and precise. I’d prove the strength of my will with this!

My speed picked up. I bent my knees, lowered my center of gravity… and—I’m not… stopping!?

“W-w-whoa—!”

I was going faster than I’d expected. Losing my balance, my body obeyed the law of inertia and pitched forward in the most pathetic way possible.

Whoosh!

A spectacular fall. This time I went headfirst into the snow.

“Ahaha! Yuuma-kun, are you okay!?”

Miru immediately ran over. Raising my face covered in snow, she looked down at me with concern, her silhouette backlit by the sunset.

“…I’m, fine.”

Trying to get up while pretending to be strong, but my skis tangled around my feet made it difficult.

Seeing my struggle, Miru suddenly extended her hand.

Her expression was hard to see due to the backlighting. But her silhouette looked like an angel descending from heaven.

I reached out my hand as if drawn by hers.

At that moment, a warning bell rang in my mind.

—Danger!

I shouldn’t take this hand. If I did, I would be swept away again. A third death was surely waiting right there.

Ignoring the offered hand, I struggled to get up on my own.

“Yuuma-kun?”

A strange voice.

I couldn’t look at her face. Just writhed clumsily on the snow.

“This is… training… for becoming a solid self…”

It’s painful even to me.

Seeing my pitiful form, Miru let out a breath and laughed.

“…Pfft. Ahahaha!”

Then she burst into laughter, clutching her stomach and tears in her eyes.

“W-what’s so funny!”

“B-but… Yuuma-kun… your worried face, your serious face, even the way you’re trying so hard like that… somehow, all of it…”

Miru said while holding back her laughter. Her cheeks were slightly flushed under the sunset.

“It’s too  adorable!”

—Adorable

That single word pierced deep into my heart.

It wasn’t twisted obsession nor fanatical worship.

It was simply warm, pure… and unbearably, irresistibly filled with affirmation.

Something inside me broke with an audible crack.

…Maybe it’s fine.

Solid self… whatever that is.

I’m tired of trying to do everything alone.

It’s too hard for me. My essence is liquid after all.

Being poured into this warm vessel… isn’t so bad.

No, it’s the best.

(…Northern country… truly terrifying…)

I gave up all resistance and lay sprawled on the snow. The sky was already darkening with the signs of night.

“Ah—sorry, sorry! I laughed too much! But I really meant it, you know.”

Saying that, Miru grabbed my arm and yanked me up with no hesitation.

“Okay! Let’s call it a day! We’ll practice again tomorrow! See ya!”

Smiling contentedly, she shouldered her skis and hurriedly left.

Left alone on the slope, I stood motionless for a while.

“My ‘Solid Self Plan’… it completely collapsed in just one day…”

I muttered. At that moment,

Looking toward the exit of the slope, I saw a single female student standing there. A classmate, the bookworm rumored to be the number one cool beauty in our grade, Himuro Reika.

She lifted her face from the paperback in her hands and cast a single glance my way. For some reason, those expressionless eyes felt as if they were shining with a sharp light that pierced straight into my depths. Then, as if nothing had happened, she calmly lowered her gaze back to her book.

(…It’s just my imagination… right? )

Though my spine tingled with a vague premonition, I brushed it aside. Now, escaping from this immediate threat was my top priority.

Vrrrt.

My smartphone in my pocket vibrated briefly.

A bad feeling stirred in my chest. Reluctantly checking the screen, there was indeed the name I expected.

—Ayabe Mirei.

“Onii, you look like you’re having fun with Yukishiro-san.”

That message had an attached photo.

The slope, dyed in the setting sun. Me—covered in snow—smiling awkwardly, and Miru watching me with a gentle, loving smile as if cherishing the whole world. It was a perfect shot.

A shiver crawled up my spine, every hair standing on end.

Another message arrived immediately after.

“The curry for dinner is getting cold.”

“Come back soon. Okay?”

My heart, which had been overflowing with heavenly warmth just moments ago, froze to absolute zero in an instant.

My Liquid Self showed no sign of solidifying, even in the freezing cold of Hokkaido.

If anything, the pressure of surveillance and the heat of innocent temptation were making it flow even faster, even smoother, straight toward ruin.

In my third life, it seemed the god of romantic comedies truly enjoyed simmering me in a pot of premium-grade hell