In the 1860s in Japan, a new era is dawning. During this time fraught with violent social upheaval, samurai of all walks of life flock to Kyoto in the hope of joining a band of warriors united around their undying loyalty to the Shogunate system. This group became one of the greatest (and most infamous) movements in Japanese history...the Shinsengumi!

When word arrives that the renowned assassin Sakamoto Ryoma is active again, the Shinsengumi must come up with a plan to stop him. Sei, still undercover as the male warrior Kamiya Seizaburo, tries to persuade her superiors that he's not the threat they believe him to be, but to no avail. Will she take matters into her own hands, despite the risk to herself and her troop?