Ryoga barely even notices at first.
At least, that's what he'd like to trick himself into believing, but the truth is he spends so much time watching Yuuma - the way he throws his head back and laughs with his whole body, the way his eyes scrunch shut when he yawns, the way his eyes slide to the side when his smiles fall flat - learning the tiny details that make Yuuma who he is, Ryoga knows immediately something isn't right.
There's a lot it could be, these days.
Ryoga watches Yuuma more closely than ever, and soon the problem is clear enough; the hunt for the Legendary Numbers is really more of a race against time. There's little chance to rest and no time at all to recover. Everything builds and builds and builds.
There are plenty of tells. Yuuma pressing a hand to his ribs, the hitch in his step as he tries to hide a limp, how he's a just a little bit slower to get to his feet each time he's down. He can't quite look Kotori in the eye as he assures her he's alright, he's fine. He shakes it off, smiles, shrugs.
Ryoga isn't the only one who notices. Astral reaches out to help Yuuma up even though they can't touch, frowns when his hands pass unrealized through Yuuma's shoulder as he gingerly retakes his feet. Kaito's concern is a nearly palpable thing, clenched hands tucked beneath his elbows, scowling hard enough Ryoga thinks his face will stick sooner or later.
Eventually, they've all had enough of watching. Yuuma staggers from the keyship's deck, body tight, fingers feeling carefully at the back of his head. Kaito and Astral go quiet as he leaves, then turn to Ryoga, staring. He stares back, not sure what it is they want until Kaito jerks his thumb at the door. Ryoga stands his ground, gestures why don't you go, asshole, but Astral's expression turns hopeful, so he rolls his eyes (as if he's not glad for the excuse) and pointedly doesn't stomp out of the room.
Ryoga finds Yuuma hunched over an open first aid kit, shirt and vest tossed aside, wincing as he presses an ice pack to the sore place on his head. He glances up at Ryoga, tries to smile. It looks more like a grimace.
And Ryoga - he freezes, clutching the doorway with enough force his knuckles turn white. Hidden beneath Yuuma's clothes, his skin is littered with bruises, patches of green and yellow slowly being eclipsed by blue and purple and red - new damage layered over old, over older still. This...this is why Yuuma's been in so much pain. There are scars too, small ones, still fresh pink. Ryoga's heart sinks, because those can't be from anything but the fight in Sargasso, the damage Astral purposely allowed Yuuma's body to take.
"Hey, Shark," he says. Ryoga doesn't think he's imagining the nervous edge in Yuuma's voice. He wonders what kind of expression he's wearing, and tries to school it into something a little less furious. "It's okay, really! I'm not bleeding or anything..."
He trails off as Ryoga reaches out on impulse to pull the ice pack away. Yuuma is probably telling the truth, but the idiot has spent so much time playing down his injuries, Ryoga needs to check for himself. The thought of leaving Yuuma alone with a serious head wound makes him feel sick. Yuuma makes no move to stop him as Ryoga probes at the area; there's a pretty big bump but no blood, and he relaxes a little until Yuuma sighs. He flushes in embarrassment, because he'd stopped checking Yuuma over and started petting his hair instead.
"It doesn't seem that bad, but don't fall asleep. You might be concussed." Yuuma nods. To avoid having to look at his friend, Ryoga shifts his attention to Yuuma's shoulder, where it's scraped up and dirty with dried blood, and gently dabs at it with a cotton ball wet with antiseptic. Cleaning away the grit without causing pain is impossible, and whenever Yuuma hisses out a breath, he hates himself a bit. Yuuma has suffered enough, and that suffocating anger is rising again so quickly it's a struggle to keep his hands steady. But Yuuma doesn't tell him to stop, actually flashes a grateful smile that he ignores, and Ryoga carries on until he's finished.
Bandaging Yuuma's shoulder takes longer than it should. Ryoga does his best to keep from pressing on the bruises, works around the scars (he hasn't forgiven Astral, not sure if he ever will; this is not how some sane reacts to a genuine mistake made with, he shudders, good intentions).
Now Yuuma is watching him, curious and slightly confused.
There's a scratch high on Yuuma's cheek, and Ryoga smoothes ointment across it with his thumb. A moment of stillness passes as Yuuma closes his eyes and nudges his cheek against Ryoga's hand despite the bruise blooming there, and then Ryoga cups Yuuma's face in his palm, soothes the hurt with tender fingertips. Yuuma's head sinks to his chest.
Ryoga shakes him. "Oi, dumbass, what did I say about sleeping?"
Yuuma blinks his eyes open, and when he smiles this time, soft and warm and real, Ryoga is pathetically glad he can give Yuuma even this small comfort. The younger boy leans in to press a kiss to the tip of Ryoga's nose with a quiet thank you and Ryoga tilts his mouth up in some sort of instinct he shouldn't have but he's been so stupid for Yuuma for so long he can't deal with this anymore.
He waits without breathing as Yuuma shifts to curl up in his arms so Ryoga can hold him close, and then nothing else registers because Yuuma is kissing him after all this time, and there's nothing more important than the dry press of their lips, how Yuuma's are chapped and sore and loose with exhaustion.
"You really are concussed," Ryoga mutters when Yuuma pulls away, wants to frown but can't, because he's an idiot. But Yuuma laughs and he can feel the hot huff of air against his mouth, so he figures it's alright.
Yuuma tucks his nose under Ryoga's chin and sighs. "Ne, Shark. Do you think this'll be over soon?"
Maybe it's because Ryoga is just as tired, maybe he's afraid of how worn down and battered Yuuma is, but dread creeps up his spine and settles in his bones, absolute and inevitable and terrifying. All he says is, "It has to end some time." For all their sakes.
He's never been more wrong.