Detective Mizuhara

Kana's father. A gruff, unshaven police detective. He is introduced as the chief investigator of the murder of Kana's friend's father.

Sou manages to impress the detective with his wide range of knowledge and develops a healthy respect for his abilities. He comes to trust Sou a great deal as he often allows Kana to accompany him on trips and occasionally includes him in family events (such as attending baseball games). He reaches a point where he is no longer surprised to see Sou and Kana together most of the time.