BioHanzo was the chieftain of the Ninja Village until he passed on that roll to Ippei when he retired at the villages festival. He was captured by Kagetomo who wanted to take control of the village but Hanzo was rescued by Ippei and the others from the village.
As a leader of the Village, he would give advice to the Ninja's and villagers as well as train and protect them. Due to his age, he decided that the roll needed to be passed on to someone else. Kagetomo at one point was considered the favorite for the roll but he strayed from Hanzo's teachings and the mission of a ninja to keep training together with Pokémon, to pursue the potential of Pokémon and to utilize it for the sake of the world, for the sake of others. Hanzo refused to give the ninja symbol to Kagetomo for those reasons.
After retiring, Hanzo stayed at the Ninja Village.