Masao is a member of Kyōshirō's pack and one of the youngest.
Ginga Densetsu Weed
He was left with The Kōga Elder along with the other puppies from his pack.
Later he and the others joined the fight against Viktor and the other Russian Army Dogs.
Hybrid Bear Arc
He participated in the battle of hybrid bear against.
Ginga Densetsu Weed: Orion
Masao and Ou army have caught in the volcanic eruption. He survives and is one of the Ou army Kurohabaki Jinemon locks the mine.
The Ouu Army
Later, the dogs are released and they participate in the final battle Kurohabaki Masamune against the troops.
See more pictures in Masao/Gallery