Prologue: The childhood friend and her little sister’s tutor

“What’s that look for?”

“Uh… well…”

Not long after Aisa and I took turns getting sick, I found myself coming over to tutor Manami.

That’s right, I was supposed to be tutoring Manami.

That’s how it was supposed to go… but for some reason, Aisa was already in the room.

“Oh, I’m the one who called Onee-chan today!”

“Why, though?”

“Hehe!”

That’s not an answer.

When I glanced at Aisa, wondering if she was okay with this, she seemed to misread me and said, with a terrifying expression:

Her face was downright scary.

“If I’m in the way, I can go back to my room…”

“You’re not in the way!”

“R-really…”

Aisa, who had started to stand, tucked her hair behind her ear and sat back down.

I’d denied it a bit too forcefully.

I wasn’t even sure why I’d done that…

“Um… thanks for taking care of me when I was sick.”

“Huh!?”

I’d said it to fill the awkward silence, but it only made the air between us even weirder…

“Fufun! Was it the maid outfit that won you over?”

“Wha—!?”

Aisa hugged herself protectively, glaring at me sharply.

“Now, now, Kou-nii’s happier with Onee-chan here, right?”

“Uh…”

Manami’s sparkling eyes locked onto me.

Aisa, meanwhile, kept up her piercing glare.

As I fumbled for a response, a savior appeared.

“Fufu, since you’re always working so hard, today you can just keep an eye on Manami to make sure she doesn’t slack off.”

Aisa and Manami’s mom—who’s so youthful I hesitate to call her “Auntie”—brought tea into the room.

“Thank you.”

My thanks were for the tea and for smoothing over the awkward moment…

“But still, is it tough handling both of them at once?”

“Why are you counting me in that!?”

“Oh my, my. Anyway, Kouki-kun, it’s fine if you focus on your own studies too, okay? You’ve got school coming up soon.”

“Oh, right, school.”

I remembered there was that one day during summer break when we had to go to school.

And with that, I recalled the pile of homework due on that day.

“Kouki-nii, have you finished your homework?”

“I’m mostly done with what’s due for school, but…”

The real concern was Manami.

“Hehe!”

“Don’t just ‘hehe’ me! You’re finishing this much today, got it!?”

“Ehh, Onee-chan, you’re so strict…”

Oh, I get it.

That’s what she meant by just keeping an eye on her.

“Kou-nii! Save me!”

“Hey, stop that!”

Manami darted toward me, escaping Aisa and clinging to me.

Aisa’s expression darkened as she watched.

“See? Handling both of them must be tough, huh?”

Seeing Auntie’s mischievous smile, I couldn’t help but think how strongly the family resemblance ran.

◇

“Break! I demand a break!”

We’d all been working on our remaining homework for a while, but Manami finally threw in the towel.

Well, she’d actually done pretty well.

Once Manami got focused, she was unstoppable. Even today, what had seemed like a hopeless pile of homework was visibly shrinking under her efforts, with Aisa and me watching.

“You worked hard, so a short break’s fine. Aisa, you good?”

“Sure.”

The moment Aisa agreed, Manami flopped onto her back, sprawling out.

“I’m sooo tiiiired!”

“Fufu, but you did great, didn’t you?”

Aisa’s expression softened as she praised Manami.

“I demand a lap pillow!”

Probably got “demand” from some vocab in her language arts homework…

I watched the scene fondly until Manami scooted over and plopped her head onto my lap without asking.

“Hey…”

I really didn’t want her getting too clingy in front of Aisa…

She’s gotten better, but Aisa can still be scary when she wants to be…

“Ehh, is that a no, Kou-nii?”

“Ugh…”

Manami looked up at me from my lap, and those eyes made it impossible to push her away…

“Oh, right! Kouki-nii, I’ve got something good for you, so here!”

“Something good…?”

“Hold on… here it is!”

Manami fidgeted with her phone, still lying on my lap.

I was too nervous to look at Aisa.

“Sent!”

“Sent…?”

At Manami’s words, I checked my phone…

“This is…”

“No way… Manami!?”

Aisa lunged toward Manami with such force it was like a gust of wind.

Manami was still on my lap.

Which meant, naturally…

“Ah…”

So close…

Aisa’s perfect face was right in front of mine.

Her face was so small. Her eyelashes were long. A faint, sweet scent wafted over… No, thinking about this any further was dangerous.

“I sent it!”

Manami, grinning mischievously from below, said that as Aisa and I were practically nose-to-nose.

“Kouki, delete it now!”

“Wha—!? I haven’t even seen it properly yet…”

“Just delete it!”

“Calm down! Don’t try to grab my phone!”

The image Manami sent had a fleeting glimpse of…

“Now you can see Onee-chan in her maid outfit anytime, Kou-nii!”

“Delete it!”

“Calm down, it’s dangerous!”

Aisa lunged, trying to snatch my phone.

Watching this, Manami, still on my lap, laughed and said:

“This is fun, isn’t it?”

Aisa and I froze, our eyes meeting.

Aisa’s face was bright red, her usual sharp glare fixed on me.

“What’s that look for…”

“Nothing…”

We both fell silent, unable to find words.

Manami, watching us, giggled and said:

“Hey, Kou-nii, look at the photo properly!”

“Yeah…”

“Wait, hold on!?”

I opened the image before Aisa could stop me.

There was Aisa, face flushed red, reluctantly making a heart with her hands—probably at Manami’s insistence—glaring at the camera.

“She’s cute, right?”

“Yeah… she’s cute.”

“Wha…!?”

The words slipped out before I could stop them.

“Fufun! Nice one, Onee-chan!”

“Huh? I-I mean… ugh!”

Aisa lightly pushed my chest and pulled away.

“You don’t… have to delete it.”

“Really?”

“Delete it if you want to!”

Which is it…?

“Why not make it your wallpaper?”

“No way, don’t!”

Aisa, who had turned away, whipped back around.

“I’ll send you more of Onee-chan’s cute pics regularly, but this one’s rare, so treasure it, okay?”

“Yeah…”

It’s true, this wasn’t something you’d see every day.

“Wait, Manami!? What do you mean, regularly!?”

“Oh, and I sent a bonus pic of me too, but it’s kinda embarrassing, so look at it later, okay?”

Manami tossed that out casually.

Her face, unusually red, had a fresh, almost shy charm to it.