He was once the strongest martial artist of Kanto and taught Traugott Geisendorfer who founded the franchise of gyms which Rakuei Gym belongs. He was in prison for 10 years for a crime that he did not commit. While in prison his son's business got into trouble to the point even his grandchildren were threatened. Izaya proved his innocence and let him free to save his family, managing to catch the real culprit of the crime. In exchange, he had to make a contract of 10 years with Izaya. He frequently says that he will kill Izaya after the contract ends.