Hajimari no Natsu

Shinji, Manabu and Chinatsu are neighbors and childhood friends. Because they hide their thoughts from each other, their feelings become locked inside their hearts. At that time, Manabu informed the others about "that thing". And he could trust his friends forever. But what will happen when they grow up and start to change the way they feel about it...?
(Source: Chibi Manga)
Included one-shot: I just love you.