It continues through the pre-Meiji period and refers to historical events such as the Boshin War, including the involvement of foreign governments, the Naval Battle of Hakodate, and the Meiji Restoration.

There are also references to historical figures such as Captain Kidd, Saigō Takamori, Andō Shōzan, Oguri Kozukenosuke (Tadamasa), Geronimo, and Mark Twain.

Jirō, a young boy of Japanese and Ainu descent, is a foundling raised by a kindly innkeeper and her daughter in the village of Sai on the Shimokita Peninsula.

The angry villagers accuse him of the murders, and rather than face a brutal crucifixion for the grave crime of parricide, Jirō escapes with the dagger.

She reveals that Tenkai dispatched Tarōza to the mountain Kamui Nupuri to find a rumored treasure large enough to keep the Shogunate in power.

Tarōza fought Tenkai's men on the cliff above, but lost an eye to a primitive grenade and his sword arm to Hanzou, then appeared to fall to his death.

He then encounters Mark Twain on the way the Los Angeles, heading for the island of Santa Catalina, which is apparently the location of Captain Kidd's treasure.

Tenkai suddenly reveals that Sanpei is a Satsuma and an associate of Tarōza, who was also Oyuki's father, making her Jirō's half sister.

He returns to Japan, where he uses Captain Kidd's treasure to help fund the overthrow of the Tokugawa shogunate by the combined Satsuma-Choushuu forces.

Jirō leaves Hakodate as the Imperial forces capture the city, but not before paying a silent farewell to Sanpei and his master, the samurai Saigō Takamori.

The unedited version, in Japanese with English subtitles and bearing the title The Dagger of Kamui, was later released on VHS and DVD by AnimEigo.

She praises the "clever script", fluid animation and battle scenes, calling the film "a good old-fashioned epic".