In the volatile atmosphere of Bakumatsu Kyoto, the Shinsengumi maintain order with the secret assistance of a mysterious kunoichi. Meanwhile, a rookie ninja named Ayame is tasked with infiltrating the circle of lordless samurai, using seduction to extract the location of a secret meeting at Ikedaya. Her intelligence leads to a violent raid by the Shinsengumi, leaving her target betrayed and heartbroken by the woman he thought he loved.
Kikyou and Kaede undergo rigorous training designed to strip away their emotions and transform them into heartless tools of assassination. When Kikyou is ordered to kill the revolutionary Sakamoto Ryouma, his vision of a world where people can live freely conflicts with her duty as a kunoichi. As the Shinsengumi track her movements to prevent a political frame-up, Kikyou's struggle between her training and her heart leads to a tragic confrontation.