As a member of the Choshu clan, Kusaka Touma aspires for Japan to build strong ties with foreign countries. To this end, he secretly studies English without his clan's knowledge. Akizuki Keiichirou, who works for the rival Tokugawa bakufu, chooses to become Kusaka’s tutor. However, their relationship evolves into something deeper despite their opposing allegiances.
Akizuki possesses a mild and gentle demeanor, so much so that he cannot bring himself to draw his sword even when his life is at risk. Despite his pride, he refrains from committing suicide due to his love for Kusaka. When Akizuki is in danger, Kusaka hides him in a cottage near his home and takes care of him, even though he feels despondent. Because of Akizuki's repeated attempts at suicide, Kusaka constantly watches over him, continuing to love him fervently.
