After his family went missing by demons called D Hazards, Shu then became a PMC, private military company, contractor whose goal is to solve that mystery. He has a contract with Kisara, an A-class demon, who helps him to exterminate D Hazards. This involves kissing the demon to obtain her power in exchange for some of his memories. A love triangle develops between Shu, his ex-girlfriend Ayano, who is also a PMC contractor, as both still love each other, and Kisara whose great power will slowly reveal little by little the truth and possibly what type of destiny they’ll have.
