As all of Edo flocks to see the work of the revered painter Hokusai, his daughter O-Ei toils diligently, creating the paintings sold under her father's name. Shy in public, in the studio O-Ei is brash and uninhibited. Seeking to come into her own as an artist, O-Ei sets out into the bustling city of Edo (present-day Tokyo), where she encounters spirits, dragons, con-men and traders.

As all of Edo flocks to see the work of the revered painter Hokusai, his daughter O-Ei toils diligently, creating the paintings sold under her father's name. Shy in public, in the studio O-Ei is brash and uninhibited. Seeking to come into her own as an artist, O-Ei sets out into the bustling city of Edo (present-day Tokyo), where she encounters spirits, dragons, con-men and traders.

Set in 18th century Japan, the film tells the story of a young lord, Asano, who travels to the capital city of Edo to assume state duties. After refusing to bribe the Grand Master of Ceremonies for teaching him official etiquette, he is goaded into drawing his sword in the Shogun's palace, a capital offense for which he is sentenced to commit harakiri suicide. This leaves the warriors of Ako as rōnin, masterless samurai, with nowhere to go and no...