Paris, 1926. Imperial Japanese Army Lieutenant Ichiro Ogami arrives in the city under orders to train a new fighting unit modeled on his famous Tokyo group. The Paris Combat Revue — the Paris Division — maintains its civilian cover as a cabaret act at the club Les Chatte Noir, while its members are also magically gifted warriors who pilot Koubu mecha. The unit's initial members are the well-meaning but accident-prone nun Erica Fontaine and the cold French aristocrat Glycine Bleumer. Ogami recruits three more: Coquelicot, a Vietnamese circus performer; the French-Japanese widow Hanabi Kitaoji; and Romanian master thief Lobelia Carlini. As the group takes shape, Paris comes under attack from the Phantoms of Paris — servants of a clown named Salut, last survivor of an ethnic group hunted nearly to extinction, who plans to use the city's guardian deity, the Great Oak Tree, to resurrect his people by sacrificing Paris's entire population. The Division defeats Salut using their united spiritual power. Throughout the training and the conflict, Ogami can pursue a romance with any member of his unit; the story's final scenes change accordingly.