Played by japanese pop singer Aya Ueto, Azumi is a trained ninja who killed her lover to prove her loyalty to her master. After her ninja group is decimated by the Shogun's forces, she goes to their fortress and kills everyone in a lenghty final battle.
The movie, shot in 2003, soon had a sequel, entitled Aemi 2: death or love, where she is still hunted by the shogun's men.
The final left an open ending for a third opus, that never came, sadly.
There also has been a musical, called "azumi returns", featuring another actress in the lead role.