Viper GTS (2002)

Carrera is a female demon whose job is to create a wish-granting contract with a human being in exchange for their soul. Along with her partners/rivals Mercedes and Rati, she carries out this job for the benefit of the demon world. When Carrera is summoned by the nerdy Ogawa, she finds him to be more interesting than her previous clients and develops a crush. In turn, Mercedes tries to get involved with Ogawa in order to compete with Carrera. However, the angels are upset by this disturbance and are willing to purify the demons with their precious "holy water" to save Ogawa's soul.