From Renta!:

Yuta Kaino is a kind office worker who's overwhelmed with his job, and the only thing he looks forward to is going home to where a freeloading guy named Hajime Himoda is waiting for him. They met when Yuta saved Hajime from a fight with a restaurant owner who accused him of trying to leave without paying, and this led to Yuta taking in the homeless and unemployed guy under the agreement that he'd give Hajime money in exchange for love. Yuta is soon hopelessly addicted to the time and physical relationship he shares with Hajime because it eases the pain in his heart. Despite them being together for a long time, Hajime won't reveal anything about his past, which makes Yuta worried. Then, just as if his worst nightmare has come true, during the Obon holiday, Hajime suddenly disappears.