The Assassin: Maria.

Maria, who lost her parents when she was young and grew up in a church, considers Father Kuros, who took care of her, as her father, and is raised as a professional hitman. A nun, Maria, who kills people at the request of her bride. She also lives with being brainwashed with the sexual playthings of Kuros, who she pretends to be meditating. Maria feels her pity and love for a similarly plighted Hayato who comes close to her, and Kurosu moves her to deal with the former killer who killed her Maria's father, but she kills her own parents. He finds out that it is her Father Kuros...