Kageyama's the one who ends up taking Hinata to the bathroom to wash his face and rinse his mouth out in the sink. The redhead is more tired than that last hit made him look; he can barely keep his feet as they go down the hall, so Kageyama keeps eyeing him and almost-reaching to grab his arm when he wobbles. Hinata does manage to keep upright, as it turns out, and he's way too out of it to notice the half-hidden reflexive movements Kageyama keeps making when he stumbles.
The bathroom's empty when they get there - it's too early for anyone else to be at school yet, much less in the gym, so Hinata has no one but Kageyama to see him splash water across his face and over the back of his neck. His hair is already damp with sweat, but the smaller boy ruffles a handful of water through it anyway, until the usual soft spikes are even more disheveled than usual. His eyes are shut, mouth open while he gulps in air and face dripping with water from the sink, so he doesn't see Kageyama's movements stall, doesn't see dark eyes following the trickle of water down the back of his neck and under the collar of his shirt. Kageyama doesn't realize what he's doing until the droplet vanishes under cloth and he blinks and comes back to himself, flushes and glances quick at Hinata to make sure he wasn't caught.
Hinata's eyes are still shut - Kageyama's safe, then - and as the taller boy exhales in silent relief the redhead comes up from the sink, shakes his hair back to send a spray of fine mist out into the air before grabbing the bottom edge of his shirt and pulling it up to dry his face. The shirt pulls up high over his chest, and it must be almost soaked through with sweat but Kageyama doesn't move, even though he has a towel in his bag, even though he was reaching for it a moment ago. He just goes still, eyes dropping to the pale skin Hinata is unselfconsciously displaying, watching the way the smaller boy's stomach flexes as he moves his arm. He's still watching when Hinata drops his shirt, turns back around with his eyes still sparkling with the afterimages of his immediate joy back on the court.
"Thanks for setting for me," he burbles, all delight and smile so bright and wide it hardly seems possible he was puking in exhaustion not five minutes before. "I've never had a teammate set for me before, it was amazing!"
Kageyama's staring at his eyes, the bright delight in the hazel a perfect match for the curve of Hinata's lips in his grin and the resonant pleasure in his voice.
"Here," is what he says, instead of "You're welcome" or even "Are you okay?" He sticks his hand out, awkward and stiff with the intent of the motion, and Hinata looks down from his eyes and Kageyama can breathe again.
"Oh." The redhead reaches out to take the proffered juicebox. His fingers brush against Kageyama's and the other boy jerks his hand back so fast the box nearly drops before Hinata can get his grip steady on it.
"Your mouth probably tastes disgusting," Kageyama offers as an explanation, crossing his arms over his chest as the best defense he can currently manage. "It'll help."
Hinata looks up at him, shock edging out the remnants of pleasure on his face. Then he smiles again, looking a little more human this time and less like he's just had a religious experience. "Thanks!"
Kageyama looks away as Hinata gets the box open, carefully doesn't watch the way the redhead's mouth tightens around the straw, because that is ridiculous, a totally absurd thing to do, they are teammates now and he needs to not be weird. "You're welcome," he remembers to say, after a minute of silence has passed. Hinata doesn't call him out on the delay, just keeps drinking. Kageyama's eyes drift to the movement of his throat, the smooth motion of swallowing as he takes in gulps of liquid, and then he realizes what he's doing and looks away again as his cheeks get hot.
He feels like the silence is heavy with meaning by the time Hinata finishes. Apparently the feeling is not mutual, though, from how easily the redhead speaks. "Thanks a lot, I feel much better."
Kageyama risks a glance. Hinata looks better, too; there's color back in his cheeks and he's breathing a little easier. He smiles at Kageyama, easy and unforced, and Kageyama stays where he is as Hinata comes towards him to toss the box into the trash can just at his elbow.
"Think we have time for some more practice?" Hinata asks before looking up from Kageyama's elbow. "We should still have an hour left, right?"
Kageyama opens his mouth to say something, about rest or overwork or something, but Hinata's very close, there are traces of gold under the brown of his eyes, and he can't think, and Hinata goes on talking.
"Maybe you could give me another toss. The last one was amazing, I'd love to practice some more before tomorrow!" He's still a little shaky on his feet, Kageyama can see him swaying very slightly, and he's still hasn't quite caught his breath, and his skin is damp from the sink, and his eyes are alight like Kageyama has never seen before.
"Hinata," he says, to say something about any of these multiple reasons not to keep practicing. And he leans down, and forward, and his mouth lands on Hinata's. Hinata's lips are still parted from his attempts to catch his breath, damp with water and faintly sweet from the juice, and Kageyama's hands unfold from his chest and his fingers come in against Hinata's neck, push up hard into the other boy's half-wet hair. Hinata exhales, sharp and surprised, into Kageyama's mouth; Kageyama groans before he can catch the sound back and jerks away, snatches his hands back like he can deny what they were just doing. There is nothing but shock in Hinata's eyes in the moment Kageyama lets himself look before he spins away, stunned caramel-gold gaze and open mouth with no words coming.
"Come on," he says, throat choked so he can't even pretend to be unaffected. "Come on, we'll practice some more."
There is a pause so long Kageyama is terrified, terrified, that Hinata is going to say something, acknowledge that he just kissed the other boy or ask why or point out any number of issues that Kageyama doesn't have answers for. He can hear Hinata close his mouth, hears the hard swallow from over his shoulder.
"Okay." Hinata sounds almost normal, much closer to ordinary than Kageyama did, and the taller boy shuts his eyes in gratitude for a moment.
"Thanks," he mumbles, so soft Hinata can ignore it if he wants.
The redhead doesn't say anything, but as they leave to head back to the main gymnasium floor his hand brushes against Kageyama's wrist, knuckles just skimming over skin, and Kageyama's breath hitches and he almost smiles before he refocuses on composing his expression before they rejoin the others.