A legendary ninja in the Kiryu Clan, Kenzan, engineers his disappearance in front of his ten-year old son, Kagerota, telling him that they will only meet again when Kagerota has grown up and polished his own ninja skills. Upon reaching maturity Kagerota has become a rogue ninja that is hunted by agents sent by the aged clan leader, Katsuragi, to get back the scroll Kenzan is thought to have taken with him which details how to shape-shift and vanquish enemies. Finding a cat that has a red nose like Kenzan, Kagerota deduces that his father has shape-shifted himself into the cat, so he calls it "Father" and begins to look after it as he dodges clan agents including the female ninjas Momiji and Tsubame.