日々も積もれば恋とな Hibi mo Tsumoreba Koi to naru

Argumento

When he was young, Oto would visit his grandma in the summer. But, because he was from Tokyo, Oto had no friends to play with and sat alone in the shade. That was until a boy two years older named Sora came and invited Oto to play with him and his friends.

To Oto, Sora was his knight in shining armor and was destroyed when he disappeared the following summer, making Oto regret not communicating his true feelings for Sora.

Several years pass, and it's finally Sora's last year of high school. All he wants is to focus on studying for his university entrance exams. Sora thought his only distraction would be his loudmouth best friend, but on his first day back, he runs into an old face - or rather, that old face runs into him, professing his love for Sora all the while.