Oni-san Dochira? Koushoku Haraishi to Toraware no Oni

A female demon, Tama, is held captive by Mutsu, a handsome, ruthless exorcist with a horrible personality. She is forced to help Mutsu with day to day chores as well as finding clients for exorcisms. One day, she tries to escape while Mutsu is asleep, only for him to wake up and force himself onto her. As his hands wander under her clothes, Tama, unfamiliar with her own body, is unable to contain the pleasure she feels. She melts into a puddle after her first "mating" experience...especially after seeing certain expressions on the face of such a brutal man!

(Source: Renta!)