Mama Fujoushi's manga / #Demon(2)

Kid who thinks he won't find anyone signs up for dating service only to end up in a motel room and being filmed for sex. Accidentally summons a demon who scares the guy away then refuses to leave. They spend a lot of time together and eventually fall in love.

Not for the faint of heart. Some gore. Demons/werewolves and the humans they fall in love with.