He is son of Akakabuto.

Ginga Nagareboshi Gin

While Hidetoshi Sekiguchi was hunting for Akakabuto, he came across a bear that he thought was him. Hidetoshi commanded John to confuse him and then attack as the bear lunged forward Hidetoshi shot the bear in the head killing him instantly. Hidetoshi believed he got his revenge for what Akakabuto did but upon closer inspection Hidetoshi sees that the bear has two eyes but akakabuto has only one. it was just one of his offspring.