A pragmatic and level-headed young man. He initially doesn't believe in the existence of yokai, but as he gets caught up in a series of eerie events, he gradually comes to face their world. While he maintains a realistic perspective laced with sarcasm and doubt, he is fundamentally compassionate and kind, unable to abandon those in need. His growth and changes are depicted as the story progresses. He is Kitaro's adoptive father. He is fond of Kitaro and Gegero.

An enigmatic man with a carefree attitude and an elusive air. He possesses the power and knowledge of a yokai but moves through human society in disguise. He often speaks in a light, jesting tone, but behind it, he calmly assesses situations and can make harsh decisions, revealing an unfathomable side. He is a character in whom kindness and danger coexist, portrayed as a key figure deeply involved in the core of the story. He loves his wife, Iwako, and his son, Kitaro. He adores Mizuki.