Kageyama doesn't get embarrassed, Hinata has discovered. Like, ever.
He'll fall asleep in class sitting straight up with his eyes still open, the whites showing when they roll to the back of his head, and all his classmates laugh and pose for pictures with him. When he wakes up, he blinks at them in a daze, yawns, and then goes about his business.
He has shown absolutely zero shame discussing his bowel movements in front of people, up to and including Yachi, for which Tanaka and Nishinoya have given him several stern lectures.
He says stuff like "Even if it takes you ten years, or twenty, will you still stand with me? Even at the top of the world?" Most high schoolers would show a healthy amount of mortification, practically proposing to their crush and eventual boyfriend-to-be as abruptly as that, but not Kageyama Tobio. He's immune.
Hinata, in contrast to Kageyama, is easily embarrassed by everything. He gets embarrassed when he's called on in class and doesn't know the answer (so, every single time), he turns red when he has an upset stomach before games, he starts stammering and shouting apologies when he hits the net with a bad serve. The time he puked in Tanaka-senpai's lap on the bus on their way to a practice match, he almost died. It doesn't keep Hinata down for long, but he and Kageyama are like night and day when it comes to this stuff.
So of course, when Kageyama confesses to Hinata (he just did it out of nowhere, too), it takes Hinata at least three minutes to stop hiding behind the volleyball he's holding to accept his confession, and another two minutes to start breathing properly again. Kageyama has to say "Oy, dumbass," no less than four times in order to snap him out of it. When Hinata finally looks up at Kageyama, he's met with the usual severe frown he knows so well (and is weirdly fond of).
"So, do you want to?" Kageyama asks him.
"W-w-w-want to what?!" Hinata yelps, sounding more like he wants to fight than accept or reject the confession letter Kageyama has shoved into his hands: I like you. Do you want to be my boyfriend? It's written on the back of a quiz Kageyama got back that day. The whole confession must not have been extremely premeditated. Also, Hinata notes, Kageyama failed the quiz.
"Go out with me," Kageyama says.
"Oh," Hinata wheezes. "Yeah."
Kageyama nods. "Cool."
And that is that.
It's shortly after the Boyfriend-ing that it happens. See, that's the thing—judging from the incident in which they started dating, Hinata really has no reason to believe Kageyama is going to start acting any differently.
This is what he thinks, anyway, until Kageyama proves him wrong.
They've planned an anime-and-study night, which means they've planned an anime night, which means Hinata is staying over at Kageyama's. They're both staring fixedly at the TV, so Hinata isn't looking when he blindly pats the sofa cushion next to him to grab another pocky stick. Instead of a cardboard box, his hand lands on Kageyama's.
"Oops, sorry," Hinata says. Kageyama doesn't respond.
Hinata glances at him, and does a double take. Kageyama isn't watching TV anymore—he's staring at his hand like he's never seen it before. His eyes are wide and unblinking.
And then, as Hinata watches, he turns slowly and obviously pink.
Hinata's mouth falls open. "You're blushing!"
Kageyama startles, like he hasn't even noticed what's happening. "Shut up!" he snaps. "I'm not!"
"You are! You look like you got sunburned!" Hinata says, pointing, and Kageyama turns to face the whole opposite direction.
"You need to get your dumb eyes checked," he says.
"My dumb eyes work way better than your—your dumber ones," Hinata says with finality, "and I don't need to get them checked to see that you're blushing."
He can't believe it. Kageyama is embarrassed. It has to be a first.
Slowly, Hinata reaches out, and puts his hand back on Kageyama's.
Kageyama spins around immediately, but weirdly, doesn't pull away. He is most definitely still red, and his mouth is wobbling, a bit like it does when he wants to smile, except right now he just looks kind of terrified. He stares at Hinata like he doesn't know what to do.
"Why are you being like this?" Hinata asks him.
"Why do you keep holding my hand?" Kageyama fires back.
Hinata freezes mid-sentence. He looks down, to where his hand rests on top of Kageyama's larger one.
"Stop yelling!" Kageyama shouts. He looks like he might fling himself underneath the sofa at any second.
Hinata can't believe this has just happened—he just started holding Kageyama's hand like it was no big deal and Kageyama didn't even say anything, he just let Hinata humiliate himself. Some boyfriend.
"I'm g-going to get ready for bed!" Hinata squeaks, almost tripping as he stands in his haste, about to run away—
A pair of arms grabs him solidly from behind, and he thinks that this is it. Now that he's been the first and only person to see Kageyama embarrassed, Kageyama can't let him live. Maybe he's not the first and only person. Maybe all the other people who embarrassed Kageyama are already dead.
Kageyama steps closer, and Hinata freezes.
"I'm sorry," he says.
"I'm not mad," Kageyama says.
"Are you sure?"
"Do people give hugs when they're mad, stupid?"
"People don't call other people stupid when they aren't mad!" Hinata protests. "Wait, is this a hug?"
"M-maybe!" Kageyama says. "Obviously!"
Hinata covers his face in his hands. He can't handle this.
"Stop getting embarrassed," Kageyama says. "Stop."
"You stop," Hinata tells him. "You never get embarrassed, so why now, suddenly?"
Kageyama doesn't answer him. He just squeezes his arms a little tighter around Hinata's waist. He's very warm—Hinata had already known this, because it's not like he hasn't been close to Kageyama before, or never touched him. He's given Kageyama high fives, and grabbed his arm when he needed Kageyama to listen to him, and Kageyama always tries to squash his head when he's annoyed, or fight with him to catch him when Hinata pisses him off. Hinata has dogpiled right on top of Kageyama after they win games before. Why is this so different?
"Because I'm really happy," Kageyama says, almost like he's answering Hinata's thoughts. It takes Hinata a moment to realize it's in response to his earlier question.
"You mean… because of this?" Hinata asks slowly.
"Yeah," Kageyama confirms. "Because of you, I guess…"
Hinata presses his palms even harder to his face. He can feel the heat bleeding from his cheeks. "Me?"
Kageyama shoves his face into Hinata's neck and nods.
"Why… why does that embarrass you, though?" Hinata asks.
"I don't know," Kageyama mumbles into his neck. "I'm just—I'm not used to it."
"Oh," Hinata says. He turns slightly, glancing through his fingers. He is met with a faceful of black hair. Tentatively, he nudges Kageyama's head with his own. "Well, I'll make sure you get used to it, then."
Kageyama finally peeks up at him. His forehead is still red. "Hugs?"
"Yeah," Hinata says. "And being happy."
Kageyama nods. "Okay."
Hinata grins. His face still feels kind of warm, but whatever, so is Kageyama's. He drops his hands and then, carefully, hooks their pinky fingers together. Kageyama acts like he doesn't notice, but Hinata knows he does.
"Wanna watch more anime?" he asks.
By the time they make it to the end of the season, Kageyama's hand is warm in his, all their fingers laced together. The tips of his ears are still pink, but Hinata thinks, maybe it's not because he's embarrassed.
He thinks Kageyama is just happy, and that makes Hinata happy, too.