In the 37th year of the Meiji Era (1904), during the Russo-Japanese war, the little Japanese army, in need of aid, utilizes their unique flying (due to a benign demon) ship, the Amanohara, to assault Russia's important base at Port Arthur (Lushun). Umakai Shintaro, a Russian ambassador born in Japan, defected and moved to Sapporo to teach at a ladies' boarding school. That females academy, however, is not like any other—it is on board the Amanohara, and the five girls Shintaro teaches are known as the Raimu Unit—girls with the capacity to call mighty monsters to fight for them. Shintaro finally becomes their tutor and war commander, and the six embark on an odd and immensely sensual odyssey as Shintaro assists the six.