Since high school, Kento Amano has been madly in love with his senpai, Ryousuke Momo, a person who does not want romantic ties with anyone and refuses to have serious relationships: he is only interested in sex. Kento is convinced that Ryousuke acts this way to fill a void, so he decides to do everything possible to make him happy – but Ryousuke continues to reject his attempts again and again 'til eventually they stop seeing each other.

Years later, starving and homeless, Amano meets again his beloved senpai by chance. Ryousuke, upon seeing Amano in such bad shape, offers him room and board, as well as a job. Amano is very excited by the idea of living with Ryousuke but he clearly warns him: as of today you are no longer my kouhai, you will be my servant! On the other hand, Amano begins to realize all the obstacles he will face on the way, not to mention the men who pass by Ryousuke's bed… Can he bear it?