For high schooler Akita Nanashi, the world is a cold, predictable cycle. Carrying heavy burdens from his past, he lives by a simple rule: keep your head down, focus on survival, and avoid making connections at all costs. To Akita, friendships are just a distraction, and hiding behind a book at his quiet window seat is the only way to stay safe.

Then comes Sayuri.

Bright, persistent, and dangerously observant, she isn't afraid to break every rule in Akita's book. The moment she barges into his lunch break—demanding to know why he sits alone—Akita's quiet, invisible life begins to crumble.

Before he knows it, he's dragged into awkward conversations and a world he thought he'd permanently locked away. But as his gray routines begin to gain color, Akita realizes that opening his heart comes with a cost.

Is staying isolated really protecting him... or will learning to care for someone mean facing a heartbreak he isn't prepared for?