The story takes place in the 30th year of Taisho. The leader of the Imperial Flower Group, Kamiyama Seijuro (voiced by Azakami Yohei), went abroad on official business, and Amamiya Sakura (voiced by Sakura Ayane) served as the acting leader. However, Kamiyama suddenly returned to the group before his term was over, and brought back a strange girl named Clara (voiced by Hayami Saori). Clara belongs to the Moscow Flower Group. Her group was wiped out due to an accident, and Clara was the only survivor. The carefree, violent shrine maiden Hatsumi Shinonome (voiced by Uchida Maaya), who is as rude as a boy, the genius ninja Mochizuki Thistle (voiced by Yamamura Hibiki) with a super high IQ, and the tall and heroic Palma (voiced by Fukuhara Ayaka), who is popular with both men and women, the members of the Flower Group work together to try to investigate the truth of the destruction of the Moscow Flower Group.