The next day.

I headed to school as usual, but then, I was greeted by a shocking sight in the classroom.

“Kazuto-kun, good morning! The weather’s nice, isn’t it?”

“O-oh… morning, Aoi. You seem really energetic… actually, did you lose some weight?”

Aoi came over to the seat next to mine and greeted me like he always did.

But his voice was unusually lively and bright.

And yet, when I looked closer, his cheeks seemed slightly sunken—while his expression alone was strikingly bright. He looked nothing like the Aoi from yesterday.

“…Aoi, did something happen to you?”

“Hehe, you can tell…?”

It was a strange smile.

It was as if his entire body was brimming with confidence.

◇◇◇

And then, after school.

I invited Aoi and Kokonoe over to my place again today.

Somehow, the three of us had completely become the usual group.

“Huh… Hareruya-kun, you seem a little different.”

“Right? You noticed too, Kokonoe? And get this—today he even casually greeted other girls. There’s no way the old Aoi could’ve done that.”

It seemed Kokonoe had noticed as well.

The sunken look in his cheeks had already returned to normal by evening, and his energy had skyrocketed.

“—It’s all thanks to you, Kazuto-kun.”

That sudden comment caught me off guard.

Aoi’s cheeks tinged slightly red as he hesitated before speaking.

“I wasn’t sure whether I should say this… but I want to tell you both properly.”

Something must have happened last night.

That much was obvious from the drastic change.

And then the words that came out of Aoi’s mouth—

They went far beyond anything I had imagined.

“—Last night, I had sex with my sister.”

Kokonoe and I froze completely.

Hearing something like that from the same Aoi who used to be afraid of girls was something I’d never even imagined.

“A-Aoi, your sister… you said she likes to make you cross-dress, right?”

“Yeah. she’s the one I mentioned at your place, Kazuto-kun. We’ve always been close since we were little. Whenever I seemed under a lot of pressure, she’d worry about me… and then, last night… when I was doing what I’d heard from you—masturbation—she caught me…”

Just imagining it made my stomach churn.

If it were me, I wouldn’t be able to face anyone at home ever again.

“Eh… b-but she’s your sister, right? Th-that’s…”

“It’s strange, right? But she kept questioning me… I didn’t mention your name, Kazuto-kun, but I told her about sex between men and women you told us about yesterday. My sister… she believed me.”

“Seriously… she’s way too accepting. Also, you’re closer to your sister than I am with my own, aren’t you?”

I’d thought she was just an older sister who just liked messing with him and making him cross-dress.

But in reality, they were connected more deeply than family.

“S-so, th-then… h-how was it!? I-I really want to know!”

Kokonoe suddenly leaned in close.

The intensity of her expression was almost frightening.

“Um… i-it felt so good I couldn’t think straight at all. …Since my parents were downstairs, I had to keep my voice down… a-and… w-we did it over and over again…”

“W-w-wow…”

“Aoi… you’ve become a man, huh.”

Now I understood why Aoi had changed so much in a single day.

And why he’d looked so worn out that morning.

—Yeah. That would do it.

“So how was your sister? Was she okay?”

“Yeah. My sister’s a college student, you know… and she actually has a boyfriend. But she said it felt several times better than when she did it with her…”

“A-awawawa…! S-so, does that mean… sex between a man and a woman is… way more pleasurable than between girls, right?”

Given what she knew, the question made sense.

Aoi’s experience with his sister had ended up serving as one possible answer.

Still, I didn’t think it was that simple.

“Kokonoe, that’s not quite right. Even in my old world, people talk about ‘compatibility’ all the time. It probably felt that good because Aoi and his sister have high physical compatibility.”

“H-huh… I see… compatibility really does matter…”

“My sister told me… it’s completely different from a uribou. It’s firm, but soft at the same time, and warm… she said it really felt like being physically connected to the other person.”

Aoi’s words sounded strangely vivid.

And yet, in this yuri-centered society, they almost came across as something mystical.

Maybe Aoi was the first person in this era to experience sex between a man and a woman.

“That’s incredible…! Even if your partner was your sister, I’ll support you with everything I’ve got!”

“Thank you, Kokonoe-san. But my sister said that if I ever find someone I truly love, I should be free to choose.”

“To be able to say that in this society… her level of understanding is incredible. You should treasure her.”

“Yeah. I really love my sister… Well, it’s definitely not something I could ever tell our parents.”

Aoi smiled shyly.

Yeah, this definitely wasn’t something you could report to your parents.

“By the way, I’ve gotta ask—your sister, Aoi… is she beautiful?”

It was common knowledge that Aoi was an exceptionally pretty boy.

If that was the case, it was only natural to be curious about his sister.

“Hm? My sister? Hehe… she’s always been really popular. She hasn’t been single since middle school. Here—look.”

Aoi pulled out his phone and showed us a photo.

“N-no way…”

“Woooow…! She looks just like a model!”

In the photo was an overwhelmingly beautiful girl with long, flowing blond hair, the same color as Aoi’s.

The resemblance was unmistakable, but she was unmistakably an adult woman.

As Touka said, she looked like a model—or even an actress.

“T-this is your sister…? And you actually did ‘that’ with her?”

“Haha… I guess I’m just used to seeing her since we’re always together.”

If he saw such a beautiful sister every day, it made sense that girls changing in the classroom wouldn’t faze him anymore.

Of course, he’d built up a tolerance.

“Hah… looks like Aoi beat me to it…”

“But in my case, it was with my sister… Still, I’ll always be cheering you on, Kazuto-kun.”

“You know… at first I had no idea how things would turn out, but I’m really glad we ended up in the same class. I’m honestly glad you became my friend.”

“Me too. Ever since I met you, Kazuto-kun, every day’s felt exciting… I can finally say I’m having fun.”

“Hearing that… actually makes me really happy.”

At this point, we were more than just friends.

He was someone I could call a best friend.

“W-w-w-wah…!”

“Hm?”

Kokonoe turned toward me, her face bright red, stumbling over her words.

Then, as if she’d made up her mind—

“—P-please have sex with me!!”

With her eyes squeezed shut, Kokonoe blurted out her plea in a trembling voice—only for it to turn out to be completely unexpected.

And she did so without hesitation, even with Aoi standing right there.

I’d made it clear again and again that I liked Asuka. So why couldn’t she hold herself back?

“K-Kokonoe… I told you I like Asuka. That’s why yesterday—”

“I-I’ve been feeling strange lately! I can’t get you out of my head, Fukase-kun… but because you like Otomi-san, I kept forcing myself to hold back…”

I have Asuka.

We had spent so much time together, falling in love, and finally grew closer in my original world.

On the other hand, I’d only just met Kokonoe.

She was certainly attractive—and honestly sexy. I’ll admit that.

But even so, I’m not the kind of guy who can just flip a switch and start seeing her as a romantic interest that easily.

“I-I’m not saying we should become lovers or anything like that…! I just want to do lewd things! I want you to touch me, Fukase-kun!”

“Hearing that means a lot… but you get why that puts me in a difficult spot, right?”

A desperate confession made without hesitation right in front of Aoi.

This wasn’t something I could dismiss as “she just wants a guy.”

If that were all it was, then Aoi—who’s also a guy—would’ve been enough.

“…I know it’s strange for someone who’s supposed to be cheering you on to say this, but… I think it might be okay.”

“Huh? What are you talking about?”

Aoi opened his mouth after seeing my confusion.

“You know… Kazuto-kun, just your very existence is kind of an irregularity, right? So I thought maybe something like a harem might be allowed for you.”

“You… you even know the word harem?”

“It was in a book I borrowed from my sister. There were tons of stories like that in it.”

“That was a manga, wasn’t it? We’re living in the real world.”

“Aaaaahhhhh!!”

All of a sudden, Kokonoe let out a strange cry.

“T-the student council president!”

“You mean President Onikisu?”

“Y-yes! I only heard it secondhand from someone in class, but… there’s a rumor that the president keeps a harem!”

“What…? That charismatic president everyone admires?”

“That’s exactly why! There are tons of girls who look up to her…!”

I recalled the shrill cheers from the entrance ceremony.

Indeed, the president was extremely popular.

But how does that connect?

“I-if the president can have a harem… then maybe… maybe Fukase-kun having one would be… allowed too…?”

“Asuka, you know… she’s serious and pure… probably. There’s no way she’d ever be okay with someone having a physical relationship with anyone else.”

The Asuka I knew was bright, straightforward, and had a genuinely pure heart.

Even if this yuri-centered society was abnormal, her personality from the original world shouldn’t have changed.

“Then I’ve decided! I’ll try adding Otomi-san to Fukase-kun’s harem myself! And if I manage that… y-you’ll do lewd things with me too, right!?”

“Huh!? I told you not to do anything unnecessary, didn’t I!? Absolutely not—don’t do that!”

“Hehehe… looks like I’ve found your weak spot, Fukase-kun…”

Kokonoe broke into a wicked, villain-like grin.

“If you don’t want me filling Otomi-san’s head with weird ideas—ack!?”

Without hesitation, I delivered a chop on Kokonoe’s head.

“I’m not saying this to guilt you, but I’m the one who gave you the push to change your look and I’m the one who taught you about men, right…? And you’re really going to get in my way?”

“I-I am grateful for that…! But I can’t do anything about this muddled feeling inside… a-and that’s why last night, while thinking about you, Fukase-kun, I ended up touching myself…”

“Don’t just suddenly report that you were using me as ‘material’…!”

It’s unbelievable that she still blurts it out, even though she was blushing just from saying it herself.

“A-anyway, this conversation is over! Don’t say anything unnecessary to Asuka!”

“Fueeeeeee~!”

“Crying won’t help!”

“Kazuto-kun…”

“Don’t tell me you’re taking her side too, Aoi.”

“Un…”

Was Aoi planning to interfere with my love life too?

I could understand how Kokonoe felt.

But the answer wasn’t that simple.

I’d only just gotten a chance to finally convey my true feelings to Asuka.

But this conversation would become the catalyst for Kokonoe to take an entirely unexpected action.

Asuka, and the student council president.

The sexual turmoil surrounding me was quietly beginning to accelerate.