Yuri Rintaro used to work as the chief of the First Investigation Division in Tokyo. Due to a case, he resigned from the police force and moved back to his hometown of Kyoto. Now, he works as a forensic psychologist in Kyoto. After receiving requests from the police, he helps them with their investigations. His investigation method involves careful observance of the crime scenes and he uses trace techniques learned from a hunter. He met that hunter in the Rocky Mountains, USA, during his school days. His assistant in Kyoto is Mitsugi Shunsuke. Mitsugi admires Yuri and runs the website "Yuri Rintaro no Jikenbo," which records Yuri's performance.