The Ōu Army is a large pack of wild dogs in the Ōu Mountains and Gajō. The leader is known as the Supreme Commander and has control over those areas.

Ōu was originally founded by Riki, who later passed the title to his son Gin. Later on, Gin passed his leadership to his own son, Weed. But later Weed was resigned and passed his leadership to his second oldest son Orion.

The Ōu Mountains is not allowed for strangers, but with dogs is okay