Aka was one of the hunting dogs owned by Takeda Gohei, and is the son of Riki. In the beginning of the story, Aka follows his owner to the mountains with Riki and Don on an expedition. However, the hunting party gets ambushed by the terrifying bear Akakabuto and Aka was killed during a fight. Aka is not credited as Gin's older brother in the anime and is never mentioned but is shown briefly in the fight of Shiro and Akakabuto where he is killed. Aka is also the uncle of Weed, Yukimura, and Joe and the great uncle of Koujiro, Orion, Sirius, Rigel, and Bellatrix.