Agira Ryūdōin

is the father of Jakō, Rokkaku and Genshō.

Background
Sometime in the past, he fought Might Guy and was defeated. After the fight against Guy, he was badly injured and died soon after. His sons tried to take revenge on Might Guy, but in the process, they realised that they misunderstood their father.

Trivia

 * Interestingly, he has a tattoo-like arrangement of tomoe on his forehead, somewhat resembling the Cursed Seal of Heaven.