To prevent warfare, the shogunate's law of "sankin-kōtai" (alternate attendance) required all "daimyōs" to spend every other year in the capitol of Edo as hostages. While in Edo, Lord Asano was chosen to host a very important Imperial envoy during the holidays. Because he was from the countryside he wasn't accustomed to the manners required for such a fancy ceremony. The Tokugawa "shōgun"s master of ceremonies, Lord Kira Kozukenosuke was appointed to teach Asano the required etiquette. Although it was his job to do so, Lord Kira demanded a bribe of Asano. Asano refused to pay the bribe, offering only a token gift. Kira refused to teach Asano the correct manners and so he made embarrassing mistakes during the ceremony. Lord Kira began taunting Asano's mistakes and so Lord Asano lashed out with his short sword, injuring Kira.