Okada Izou… "Izou the Slayer" is coming to America!? At the recommendation of Ryoma, Izou is assigned to escort Kaishuu Katsu, the military magistrate of the Tokugawa Shogunate, to travel to San Francisco on board the Kanrin Maru with a Japanese delegation to ratify the Treaty of Amity and Commerce between Japan and the United States. At the welcoming party, Izou is upset by the arrogant attitude of his patron, Richardson, and causes a big fuss. This leads to Izou's decision to stay in the United States! He travels all the way from the west coast to Washington, D.C. Along the way, he encounters various events and historical figures…