Happy Parasite

An encounter that leads to a pushy parasite?! "Thanks for your help!" "Please leave." The cool, low energy businessman and the super-positive NEET, the worst possible match(?), start living together! "I'll repay you with my body!" One night, Kazuhisa, a company employee who doesn't like getting involved with others, meets Haru, a backpacker lying down on the street. Surprised and annoyed by his decision, Kazuhisa decided to let Haru, who had trouble sleeping, stay with him. Kazuhisa is swayed by the brazenness and energy of Haru, while he tries to take care of him the best he can. To top it all off, Haru tries to repay Kazuhisa with his body...?

(Source: Kaiousha, translated)

Note: Includes three extra chapters.