Kazumitsu is a character introduced in the third season of the anime, which takes place roughly one hundred years after the conclusion of the second season. He is the grandfather of two other new characters, Yuki and Aiko. His role is situated within the modern era that Fushi has created after defeating the supernatural beings known as the Knockers. Information about his background is limited, but he is a member of the family that forms a central part of the new story arc's setting.

Details regarding Kazumitsu's personality and motivations are not specified in the available sources. His significance in the narrative is tied to the thematic direction of the third season. The story introduces new threats that exploit human weaknesses and explores socially critical themes such as migration, generational conflicts, and societal integration. Kazumitsu's character is specifically noted as a vessel through which these themes, particularly those concerning social integration in a modern context, are brought into the story. His development and any notable abilities he may possess are not documented. Key relationships include his familial bond with his grandchildren, Yuki and Aiko.