I'm a sugarcane's manga / #unrequited love(4)

kawanata found a piece of love letter from a guys who lived upstairs, when he looked up, that guy was crying, and after that he couldn't leave him alone, especially when he know that that guy is also a coworker of his. But the guy, kosuge, has feeling for another person, a married man with a kid. When they live cross path again, kosuge was very happy, but after all it didn't take long until the wife coming back, and he being rejected. At that crucial moment, kawanata confess and ask him to think about it. After some time when kosuge has to move out bc he got accepted in somewhere else, kosuge tell kawamata that he also love him.