Sarcasm does not work on Kazamatsuri.
Neither, Mizuno finds, does subtlety.
When he hands Kazamatsuri a towel after a hard practice, Kazamatsuri just grins and says, "Thanks, Mizuno-kun!" When he fills an extra thermos of water just for Kazamatsuri, he just says, "You're the best, Mizuno-kun!" When he goes out of his way to walk Kazamatsuri home, Kazamatsuri just chatters happily and when they get to his apartment, he says, "See you tomorrow, Mizuno-kun!"
When he diffidently asks, "Won't you call me Tatsuya?", Kazamaturi smiles brilliantly and says, "Then you have to call me Shou."
Mizuno thinks, with a certain sense of despair, that he could hand Kazamatsuri a love letter, complete with pink heart stickers,confessing his affections, and Kazamatsuri still wouldn't get it.
And then one day, Shige take things into his own hands, and whispers something in Kazamatsuri's ear.
In the middle of soccer practice, a look of wonder crosses Kazamatsuri's face, and he blurts out, "I like you, too, Mizuno-kun!"
The team cracks up and Mizuno wants to sink into the ground and disappear, but Kazamatsuri is as obliviously happy as ever, and Mizuno smiles at him for a long moment before yelling at the team to get back to work.