One of the four member of the "Sacred Beast Four Family", he materializes his spirit in form of an Okami (a giant white wolf). He is the one who saved Shino, Sousuke, and Hamaji during the destruction of the Ootsuka Village. He is the one who asks Sousuke and Shino to find the other bead holders for an unknown purpose. He is cold and calm, but he most likely had a close relationship with Shino in the past, as shown in he and child Shino holding hands while walking. And he, in fact, cares for Shino a lot. Rio doesn't smile a lot, but he once smiled gently while gazing at the sleeping Shino, which was an inspiration for Daikaku to finish his dolls.