Kotohigaoka Monogatari

Oshima and Aoi are students of Kotohigaoka high school. They are secretly in love with the heroine Saeki Yuna, but can't confess to her due to constant attention and clinging of their cousin Ayaka and younger student Maiko. Events start to unwind after Aoi is recruited as a substitute basketball team member to replace an injured player.

[From vndbreview]