Kaioh was the head of the conspiracy, his plan was to conquer everything with the aid of Shougo. He acts like an adviser to Shougo. They are old acquaintances as well as devout Christians. However, nobody knows his goals.

When Kaioh was younger, he and his mother were forced to leave Japan due to the persecution of the Christians. He ended up in China but returned, years later, to his homeland for revenge. He joined Shougo and had planned the Amakusa's death. However, his plans were known and Kaioh had to accelerate his plans. Unfortunately, Shouzo showed up and killed him with some bombs from Sano made by Katsu.