A petite and slender young woman with straight dark hair that drapes to just below her shoulders, Hotarubi (蛍火) embodies the concept of the traditional Japanese beauty. Although she shares her clan's hatred for the Kouga, Hotarubi's prime concern is for her fiancé Yashamaru, another member of the Iga ten. Her devotion to him is so great that even the suggestion that he's come to harm is enough to send her into reactions that range from a mere evil stare (like when Mino Nenki makes a bad joke about it) to a feral rage (when Shougen refuses to tell her if Yashamaru is alive or not, and she brutally stabs him to death). Like most of the Iga, Hotarubi considers Oboro to be a completely useless leader and defers to Tenzen's orders. In the anime, this may be tied to slight jealousy, since Yashamaru once teased her for not being sweet and feminine like Oboro and a comically offended Hotarubi threw a childish tantrum at him.