A detective who shows interest as well as familiarity with NijÅ«-MensÅ�'s mode of operation and history.
He first approaches Chiko when she is returned to her aunt after several years with NijÅ«-MensÅ� and suggests that NijÅ«-MensÅ� is alive. After Akechi returns the Anastasia Ruby, previously held by NijÅ«-MensÅ� for safekeeping, to Chiko, she accepts Akechi's challenge to see which of the two will find NijÅ«-MensÅ� first and he recognizes Chiko as a detective by taking up the endeavour. NijÅ«-MensÅ� briefly impersonates Akechi to save Chiko from the White Haired Devil, though the real Akechi appears to afterward to chase after NijÅ«-MensÅ� when Chiko is taken by the Devil. As a detective, he is known and respected by the city police and is able to gather information on NijÅ«-MensÅ�, which he shares with Chiko. He is the first to suspect NijÅ«-MensÅ�'s prior history as scientist attempting to create the "fourth state of water" will have dangerous consequences on Tokyo, but upon finding NijÅ«-MensÅ�, Akechi allows him to leave and complete his mission and not arrest NijÅ«-MensÅ� for the time being.