Happōsai Hieta serves as the leader of the Dokutake Castle Ninja Team and also holds the position of Headmaster at the Dokutake Ninjutsu Classroom. He is characterized as a schemer with a strong enthusiasm for warfare, having earned a negative reputation due to his involvement in numerous underhanded plots carried out for the benefit of his castle and his lord. As a longstanding enemy of the Ninjutsu Academy and particularly its Headmaster, he frequently devises plans to oppose them, though his schemes tend to fail in their execution.

A distinctive physical trait is his unusually large head, which causes him to tip over backward from its weight whenever he erupts into his signature villainous laugh. This physical comedy is a recurring feature of his behavior. Furthermore, he often finds himself needing to remind others of his name, as people consistently fail to remember or pronounce it correctly. No information is available regarding his specific motivations, detailed background, key relationships beyond his enmity with the Ninjutsu Academy, character development throughout the story, or any notable combat or ninja abilities he may possess.