A young demon named Sora runs away from his own world, leaving nothing more than a note behind, and escapes into the human realm. Almost immediately, he encounters a series of harsh challenges, including being robbed of his money. After a strange man who claims to be an angel conducts a baffling job interview, Sora is picked up by the handsome and sadistic Eril, the owner of a pleasure palace called Paraiso. Sora soon finds himself burdened with an impossible debt that only his body can repay.

The central conflict stems from Sora’s profound naivety. Despite being a 160-year-old incubus, he is completely unfamiliar with human desires and has no understanding of sex or the nature of the work at Paraiso. This innocence leaves him vulnerable to Eril, a perverse angel who willingly takes on the task of educating the young demon while exploiting his absurd level of ignorance for his own pleasure and profit.

The story unfolds primarily within the walls of Paraiso, a business of pleasure where the transaction of money and physical intimacy are intertwined. The dynamic between Sora and Eril drives the narrative, as their relationship blurs the lines between debtor and creditor, employer and employee, and teacher and student. The series explores themes of transactional relationships and the collision of the supernatural with human vices, all while maintaining a foundation in comedy and fantastical elements. The manga, originally titled Ai wa Kane Nari, was published in Japan starting in 2018 and is completed with a total of two volumes.