Don't Lose Your Head!.

In 1701, an insult led to a sword slash between the heads of the Ako clan and the Kira clan in Shogun's court. The head of the Ako clan was ordered to commit seppuku, and his loyal retainers plotted revenge against the Kira clan. This led to the legendary events known as the "47 ronin incident". However, unknown to most, the head of the Kira clan, Kozukenosuke Kira, is already dead from his wounds. Impersonating him is his slacker monk brother Takaaki, who has to prevent his brother's death being found out to protect his clan – and accidentally befriends Ooishi, the leader of the Ako men who wouldn't really want to go through with the revenge. Will Takaaki survive with his head?