Koibito Koukan Nikki

あらすじ

Mana, a third-year high school student, is in a relationship with her classmate Eira, an honor student. Her wealthy and attractive friend, Aimi, approaches Mana for advice regarding her boyfriend Ren's infidelity. Aimi proposes a one-day boyfriend exchange as a way to teach Ren a lesson. This unusual arrangement soon begins to reveal unexpected aspects of Aimi's true personality.