Ryunosuke, the head of the Hojo school of swordsmanship, defies his father Ukon’s wrath; while appearing to spend his time carousing with Oshima—a teahouse waitress from Maruyama—he is secretly aiding the pro-Imperial faction and investigating a Shogunate conspiracy while disguised as a swordsman in a white hood. Eventually disowned by his father, he moves to Edo and sets up a shingle as an instructor of yokyoku (Noh chanting) while biding his time. Meanwhile, a gang of thieves known as the Seiryu-gumi is running rampant in Edo, claiming to raise funds for the movement to overthrow the Shogunate.