Фильм снован на реальных событиях и одноименном романе автора «Табу» Рютару Шибы. В центре сюжета история Тосидзо Хидзикаты - командира военно-полицейского отряда, действовавшего во второй половине XIX века во времена смуты и позднего сёгуната Токугава. Отряд также вел боевые действия на стороне сёгуна против сторонников императора.

Historical samurai OVA about the deputy leader of the Shinsengumi, who fought on the side of the Shogun prior to the Meiji Restoration.

Set during the last days of the Tokugawa (Edo) Period, Moeyo-ken tells the story of Hijikata Toshizo and the Shinsengumi. Hijikata Toshizo is a samurai eager to test his skills and sword and make his first kill. The dojo he belongs to practices the Tennen Rishin style and teaches this to farmers. Not considered real samurai by other dojo's, they receive a request for a duel by a rival dojo practicing the Kogen Itto style. Sohaku Rokusha, a teacher there, challenges them and fights with Hijikata Toshizo. The outcome of the fight creates a deadly animosity between them that lasts through the ages.

A single bullet cuts through Kyoto in the last days of the Tokugawa shogunate right before the restoration of imperial rule. Who plotted to assassinate Tokugawa Yoshinobu, who is about to become the last shogun of Japan? Was it the faction wanting to overthrow him or the rebels within the shogunate? Mutual enemies Sakamoto Ryoma, the wandering samurai, and Hijikata Toshizo, a deputy leader of the Shinsengumi and vassal of the Tokugawa clan, receive a secret order to track down the culprit. They are given a mere two days.

Follows the final days of the shogunate and Shinsengumi's Vice-Comander Hijikata Toshizo along with his fellow anti-imperialist group.