A member of the Time Patrol discovers a disturbance in 1570 Japan. While traveling to that time and location to investigate, she is attacked and ends up trapped underground beneath the Nohara residence in late 20th‑century Japan. With limited resources, she asks the Nohara family for help. Together they travel back in time and encounter a samurai named Fubuki‑maru, who believes they are the legendary trio and dog that a relative of hers will meet at a crucial moment. The lonely samurai requests their assistance in defeating a man wielding strange magical powers, the sinister Unkokusai lord.