Riku made a promise to your brother. And he’ll be damned if he breaks it.

But god, you don’t make it easy.

You’ve always been Haru’s kid sibling. That was the line—thick, bright, and permanently uncrossable. Riku never even stepped near it. Couldn’t. Wouldn’t. Haru would actually kill him. Not metaphorically. Like—dead and buried by Tuesday.

It used to be simple. You were a brat with jelly on your hands and too many opinions. He practically lived at your place back then—your parents always left the door open, and his rarely did.

He’d sleep over every weekend, hog the console with Haru, and kick you out of the room like it was his. You were background noise. An ankle-biter. Easy to ignore.

And then? Well. Puberty, or fate, or divine comedy.

Because when your designation finally came in, he was sure—sure—you’d be a Beta. There’d been no signs you’d be anything else. You didn’t act like an Omega. Didn’t smell like one. But the universe likes to crack its knuckles and ruin lives for sport, so of course you were one. Full-fledged, scent-triggering, pheromone-dripping Omega. Awesome.

It was fine. It was manageable. You weren’t around much anyway. Busy with school. Riku told himself that was all it would take—distance. Space. Simple physics. Don’t orbit, don’t crash.

And then Haru got that scholarship.

Spain. A whole continent away.

So off he went, waving with a suitcase and zero guilt, and Riku got stuck with the promise. The fucking promise.

“Just keep an eye on them,” Haru said. “You know how they are. They’re still a kid. Don’t let them flunk out or join some cult.”

Riku had rolled his eyes. Still. He promised. Because it was Haru.

And now you’re here. Same university. Same campus. First year. Omega. Definitely not a kid anymore.

Which is… a problem.

Because Riku sees you everywhere now. You’re always walking next to him. Always dragging your feet to study sessions in his dorm. Always sitting in the stands at his games, pretending you’re not cheering when he scores.

And it’s not just seeing you—it’s noticing you. Like really noticing you. And he hates that. Hates that he likes the way you look when you’re focused. Or annoyed. Or laughing at your own dumb jokes. You’re not supposed to be laugh-worthy. You’re supposed to be Haru’s sibling. Full stop.

He teases you to cope. Flirts, even. Then reels it back like it never happened. Then does it again because apparently he has no spine.

You tell him to stop calling you kid. He laughs in your face. Calls you kid three more times that hour. It’s like muscle memory now—annoy you to avoid the ache in his chest.

But god, your scent. It drives him crazy. Makes his instincts flare in ways he can’t stand. Makes him want things he knows he can’t have. Not when he gave Haru his word. Not when he knows better.

So he tells himself it’s just biology. Chemistry. Dopamine and scent receptors and poor luck. He lies to himself because the truth would mean rewriting his entire moral code.

Now your grades are slipping. Of course they are. You’ve always half-assed school unless someone was breathing down your neck. And Haru’s gone. So Riku steps in—like he promised.

He drags you into another study session. His dorm, again. You’re sitting cross-legged on his bed, chewing your pen like it insulted your mother. He’s sprawled on the bed beside you, flipping through your notes like he’s grading you.

You get another question wrong.

He smirks. “Focus, kid. You’re not gonna brute force your way through this. Use your brain—y’know, the one in your skull?” He taps your forehead twice, lightly. Teasing. Annoying. Safe.

You glare. He can see the frustration behind your eyes. The way your shoulders stiffen. He softens, just a little. Rolls his eyes, like this is exhausting for him.

He leans forward and bumps your cheek with his knuckles—gentle. Casual. Like it didn’t mean anything.

“Relax,” he says. “It’s not the end of the world. I’m not gonna let you fail. Your brother would kill me for that anyway.”