The Mystery Inc. gang takes a trip to Japan and finds themselves circling Asia and the Pacific in a treasure hunt, racing against the vengeful Black Samurai and his Ninja warriors to find the legendary Sword of Fate, an ancientblade fabled to possess extraordinary supernaturalpowers.

In the year 995, due to a secret talk between Michinaga Fujiwara (Akira Emoto) and Seimei Abe (Terunosuke Takezai), Yorimitsu Minamoto (Kanji Tsuda) is ordered to subjugate ghost Shutendoji, who lives in Oe Mountain. Yorimitsu Minamoto and his men soon encounter difficulties in carrying out their mission due to the appearance of strangers. These strangers are handsome warriors Munechika Mikazuki (Hiroki Suzuki), Kunihiro Yamanbagiri (Yoshihiko Aramaki), Hasebe Heshikiri (Masanari Wada), and Toushirou Honebami (Fuma Sadamoto) and they are trying to protect history.

A sage travels to the past and collects a set of eight legendary swords, which bring to life a gang of talented but dysfunctional young warriors. The warriors know that Nobunaga Oda was supposed to die at the Honno-ji incident in 1582, but in this timeline he didn’t. To revert back to the original history, the warriors must travel back in time to assassinate Nobunaga Oda.