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. In time, this group would become one of the greatest (and most infamous) movements in Japanese history... the Shinsengumi!

In 1867, a time of turmoil for the Shinsengumi, Councilor Ito Kashitaro's complex espionage plan is put into action. Its ostensible purpose is to gain information on the Sat-Cho alliance, but as usual, Ito's got ulterior motives. When the selection of an outside member to join the Goryoeji espionage group causes controversy among the Shinsengumi rank and file, Sei, Okita, Saito, Hijikata, and Kondo reevaluate their roles in the organization.