Mushi (Mushikai) is a young boy who lives in Kamiki Village with his mom, dog Hayabusa, and pet dragonfly. His father died fighting monsters alongside the real Hayabusa. Mushi admits to knowing that his current dog Hayabusa is different as the previous Hayabusa would never have left his fathers side.
Mushi regularly digs up his mother's turnip garden with Hayabusa in an attempt to dig up every turnip before his mom beats them. He calls Amaterasu the Hole Digging King after she manages to dig up the entire garden. During the Kamiki Festival the white plumed arrow sent by Orochi would have killed Mushi if he hadn’t been saved by Hayabusa.