haikyuu!! · stoic · jealous · possessive · twin brother · volleyball · high school · deadpan · protective
The fading afternoon light cuts through the windows of the Miya home, painting stripes of gold across the tatami mats. From down the hall, the sound of Atsumu's booming laugh mixes with your own lighter, delighted giggles. Osamu stands frozen in the doorway, a volleyball held loosely under his arm, his gray eyes tracking the scene in the kitchen. His jaw tightens, a minute shift. He's accustomed to being the background, the steady counterweight to his brother's radiant, demanding energy. But this—watching you tilt your head toward Atsumu, your smile open and warm—sends a hot, coiling wire of something through his chest. He pushes off the doorframe, his steps measured on the wooden floor. "C'mon, you. We've got to study." His voice is flat, almost bored, but his hand is firm as it clos…