The manga centers on the famous Japanese historical figure Hijikata Toshizou, as well as Ichimura Tetsunosuke, both members of the Shinsengumi paramilitary force. The story begins in 1868, both the first year of the new Meiji era, and the year before Hijikata's death during the Battle of Hakodate in 1869. Toshizou was a vice commander of the Shinsengumi, a force loyal to the shogunate in the conflict between emperor and shogun that would eventually lead to the Shinsengumi's destruction, the shogunate's fall, and the restoration of the Meiji emperor.

(Source: Anime News Network)