- 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 appears that she has feelings for Hei, or at least his civilian alias, Li.
After the events of Darker than Black and the Darker than Black: Shikoku no Hana manga, she resigns from the section and relocates to the Hachijo-Jima police station. She is then recruited into Section 3 with the alias of Yayoi Ichinose (一ノ瀬弥生, Ichinose Yayoi)