He is black and white Siberian Husky with large ball patterns in the forehead, a small black dot on the right side of the muzzle, the right cheek and the right side of the chest and has light blue eyes.
Seiryu is helpful to anyone in trouble and will follow his father anywhere.
Together with his brothers, Seiryū discovers the German Shepherd, Jerome when he enters Hokkaido. They take him to their father, where they discuss the threat of the German Shepherd, Victor who has entered Hokkaido as well. Shortly after Jerome has left, Seiryū and his brothers bump into him again. This time, Jerome is seriously wounded after a fight with Victor. Seiryū takes Jerome to the Collie, Ram, where he can stay in safety until his wounds have healed.
Seiryū then returns to their father to plan an attack on Victor’s pack to remove him from their island. However, they get ambushed during their planning, where Victor's pack attack with full force. Seiryū gets killed by Aram during the fight.