In Japan, the Tokugawa Era represents a period of change in which the country must decide on how best to deal with its relationships with foreign countries. While many believe in isolationism, especially among the Choshu faction, Touma Kusaka's ideals are against his clan's. He secretly attempts to learn English for the purpose of preparing for the future of an open Japan.

To this end, he gains an ally for his silent struggle in a man named Keiichiro Akizuki, despite the fact that Akizuki is on the opposing side, the Tokugawa shogunate. During the course of their interaction, their bond deepens into something beyond commonality.