Iouzan

Iouzan is a father of two sons and a potential successor to the throne of the beast world.

Near the end of the movie, Iouzan battles Kumatetsu to see who will become the new lord. Iouzan loses.

Later on, it is revealed that his son Ichirouhiko is actually a human boy and not a beast. Iouzan found him in the human world and decided to keep him.