Alt. title: 悪い大人になりまして ; So we became a bad adult.
From Rain over Paradise: After breaking up with his girlfriend, Natsuno is homeless and has to crash at his office. When he happens to meet his old school friend and admirer, Ui, at a wedding ceremony, he hopes to find shelter at his place. But Ui has lost his memory after an accident, and doesn’t remember Natsuno anymore…!
– chapter 1