Amanojaku

Amanojaku was once an ancient spirit imprisoned within a mountain tree by Satsuki’s mother. After regaining his freedom, he became accidentally trapped inside the body of Kaya, the family pet. While he initially displays a malicious streak and takes pleasure in the children's misfortunes, his hostility gradually fades. Over time, he develops a genuine bond and affection for the young protagonists, especially Satsuki and Keiichirou.