Posing as a man, Sei trains with the Shinsengumi and does her best to survive the turbulent times. Now officially recognized as vassals of the Tokugawa family, the Shinsengumi move to a new headquarters and unite with renewed determination to face the threat of the shogunate’s collapse. One night, Sei notices that the fierce warrior Okita is coughing violently in an adjacent room. She suspects the worst: tuberculosis. What will become of Okita and Sei, and their secret love for each other?