During the second half of the 19th century, a new era dawned over Japan. The events leading up to this new empire, however, were dark, filled with reigns of terror, torrents of pain, and showers of blood. This was the start of the Meiji Restoration. Amidst the chaos were the Shinsen Gumi, and the Ishin Shishi, a small band of soldiers trying to overthrow the Tokugawa Shogunate.
Descriptions taken from AniDB.net