Nemureru Hiru wa, Kimi no Shita

Because of the trauma Kozue has faced from the past, he has trouble falling asleep. The only way he knows is to make himself exhausted and tired. Which is why he maintains a physical relationship with his childhood friend Katsura and classmate Ibuki. But one day his feelings start to change because he caught interest in Kuwai, a boy from the same grade and same school.