Gou was a tall, muscular man with dark hair.
Gou was entirely focused on becoming stronger. He greatly enjoyed beating up students who trained at his family's dojo, and especially his youngest brother Gen, who never fought back.
It was typically Gou's idea to beat up Gen, though the other brothers were quick to join in. After Gen seriously injured the father of a local bully, Tetsusai Shishio ordered his sons to find Gen and bring him home. Though they captured Gen, instead of merely holding him, the brothers planned to drown him in a river for damaging the family name. Gen transformed and broke free, injuring and traumatizing his brothers, who from that point on considered him a monster.
- Gou's name (剛) means firm.