Kageyama tries to tell Hinata he loves him. Eventually, he succeeds in doing so.
Kageyama can't stand the thought of anyone taking Hinata from him, so he seals their relationship by demanding that Hinata start dating him. Hinata agrees, if only because explaining that Kageyama has just imprinted on him would be too difficult. As time passes, though, Hinata realizes they'll need to set some ground rules.
Kageyama and Hinata (along with the rest of the team) go to a festival.
Kageyama accidently eats a cookie with a love potion inside, which effectively makes him fall for Hinata.
Natsu accompanies Kageyama and Hinata on a date.
Hinata asks Kageyama to help him calm his nerves by letting him listen to the sound of the other's heartbeat. However, this soon escalates into more and more intimate contact, until Kageyama is certain that if he doesn't stop this right away, Hinata is going to realize that his feelings have escalated beyond that of teammates.
After finding out some information about Kageyama's past, Hinata starts feeling insecure about their relationship.
ALL THE SHIPS
Haikyuu!! - Hatsukoi Combat (doujinshi)