Tokita Yuki

An old friend of Haru's who comes to the city. Her foster father is a respected police detective, and she herself is skilled in negotiation and has studied criminal psychology. She often amuses herself by putting that skill in manipulating others to use on the people around her.

Spoiler

She is Shiratori Mizuha's half-sister. She is later revealed as being secretly in league with Maou since the beginning of the story.