Japanese voice: Emi Shinohara
English voice: Wendee Lee
As well as being an adept ninja, Kagero is also the poison taster for the Mochizuki clan. Her body is naturally resistant to poisons and toxins, making her a valuable asset to the Chamberlain. Her job has exposed her to many deadly poisons which have saturated her entire body, meaning that she cannot get close to anyone. Any man that is intimate with her or so much as kisses her will be killed by the poisons running through her body.
When the Koga are wiped out by the Kimon, Kagero is captured by the stone giant Tessai. He attempts to rape her, but is interrupted by Jubei Kibagami who rescues Kagero. Kagero then returns to the Chamberlain and informs him of the destruction of her team; the Chamberlain then orders her to continue the mission alone.
As Kagero nears Shimoda Village, she encounters Jubei once more inside a shrine being attacked by Benisato. She intervenes and manages to save Jubei and then joins him and Dakuan on their mission. They suffer numerous attacks by the Kimon but manage to overcome each of these hardships. While they appear to be hostile towards each other throughout most of their adventure, they gradually form a bond and Jubei comes to regard Kagero as a comrade.
When the heroes reach Kashima Harbour, they find a ship of the House of Toyotomi being loaded with caskets of gold. Jubei and Dakuan ponder on how to sink the ship while Kagero sends a message to the Mochizuki requesting reinforcements. The Mochizuki later arrive being led by the Chamberlain himself, but when Kagero meets with him, he stabs her in the back with his sword. The Chamberlain is actually Himuro Gemma in disguise and he reveals that he had murdered the real Chamberlain days ago.
Jubei witnesses Kagero's injury and goes to her rescue, fighting his way through Gemma's troops and slaying many of them. He grabs Kagero and takes her to an empty building, but he is unable to save her. Before she dies, Kagero kisses Jubei. Earlier in the film, Dakuan had poisoned Jubei with a slow-acting toxin in order to force him into working with him. When Kagero and Jubei kiss, the poison in her body counteracts the poison in Jubei's blood, curing him.