Amayado Rei

The biological father of the Yamada brothers, he is a mysterious man who claims to be a con artist.

He was formerly part of the military's technology development division, but left and began independently developing the Hypnosis Mic, the True Hypnosis Mic, and the Hypnosis Canceller.
While he had a mutual-use relationship with the Chuo Ward—partly to save his wife, Nayuta—he is now active as a member of Dotsuitare Honpo.

He refers to himself as 'Oichan' and hides his identity while going out drinking, showing a friendly and approachable side.