In the distant past, an evil shape-shifter named Aku brought destruction upon the land. As the citizens' last hope, a youngster is sent away to train as a samurai warrior. When he returns as an adult to confront Aku, the warrior finds himself flung into the future through a time portal, landing in an unknown time and place. The locals help him in his quest to return to the past and undo the evil brought on by Aku.