The Section-Chief of the Foreign Affairs Section 4 who is investigating matters that concern Contractors. Misaki has long brown hair and glasses and rarely smiles or laughs. She has a strong sense of justice and a sharp intuition. Kirihara became a policewoman in order to protect the weak, has a distaste for smokers due to their smell, and is sensitive about the exposure of her body. She likes eating greasy food but claims to stay fit due to constantly moving around everyday as part of her job. Her father is Superintendent Supervisor Naoyasu Kirihara of the National Police Agency.
It is hinted that she may have romantic feelings for Li Shun Sheng(Hei).
It was later revealed in the later part of special episode 26, that Hei's identity was revealed to her accidentally in a situation. In that particular episode, her subordinate,Yusuke Saito, has feelings for her and confessed it accidentally during a situation. Their memories of that incident however, was erased due to a however soon after verbalizing them his memory along with Kirihara's is erased due to a memory erasing substance accidentally released by Mao.