Kampfer

Natsuru Sen enters a high school where the genders are divided. He has a crush on Kaede Sakura, the popular student who owns an odd collection of stuffed animals called Entrail Animals that are decorated with grisly depictions of death. Natsuru realizes he has changed into a girl one day. Informing him that he has been chosen as a Kämpfer, a female warrior who must battle against other Kämpfer who are not on her squad as denoted by a colored Bracelet of Oath, his plush tiger named Harakiri Tora awakens. Natsuru draws the attention of a number of Kämpfer females at school, notably the gorgeous but cunning student council president Shizuku Sang and later Natsuru's childhood friend Mikoto Kond. Kämpfer girls include quiet bookworm Akane Mishima, who turns into a loudmouth with a gun, and Mikoto Kond. Natsuru can occasionally transform back into a guy, but because this could lead him to change, he must continue to attend school both as a male and a female student with the same name while keeping his switching identity a secret. Sakura's own intense attraction to Natsuru's feminine form and apparent connection to the Kämpfer's general formation further complicate matters. Later tales see Natsuru and the females engaged in combat with rival Kämpfer organizations. The Kämpfer are first split into two rival factions, Red and Blue, but a truce is eventually established between certain Red and Blue Kämpfer members, leading to the formation of the White Kämpfer.