Yatagarasu appears as a giant partially-mechanical one-legged corvid and has the ability to spit fortha destructive beam and fire its feathers, which become many small dagger-like kunai. He is summoned by Shiho (or, more often, Shiho's doppelganger) using her Element, a flute and is most often used to confront Mai Tokiha, with whom Shiho is at odds over the affections of her close friend from childhood, Yuuichi Tate. Yatagarasu is responsible for the final blow in the fatal attack on Gennai, Akira Okuzaki's Child, which results in the demise of Mai's younger brother Takumi Tokiha before being finally destroyed by Mikoto Minagi, which in turn results in Yuuichi's "death".
The figure of Yatagarasu is an important one in Japanese ethnogenesis: it was sent from heaven to guide the first emperor Jimmu-tenno to what would eventually become Japan. Yatagarasu is seen as the messenger of the solar goddess Amaterasu Omikami and dwells in the sun. An important figure in Japanese culture, Yatagarasu even appears on the crest of the Japanese Football Association and a badge featuring Yatagarasu is worn by winners of the Emperor's Cup the season following their triumph.
The Mai-HiME portrayal of Yatagarasu with but one leg seems to symblolise Shiho's desire to monopolise Yuuichi's attentions.