Rappa is an orphan who idolizes fictional ninja. One snowy night, he falls from a rooftop and is saved by a real ninja named Okachimachi and his master. Rappa turns up at their door asking to become an apprentice, and the three begin living together as a family. Years later, Rappa throws himself into training to become a ninja who can protect the town. The children who look up to him gather at the master's traditional Japanese candy shop, a place where he can laugh with family and friends. Rappa thinks these days will last forever, but he sees Okachimachi tending to their retired master and catches a glimpse of the pain the master has kept hidden...
