Natsuru Senō

Natsuru Senō [瀬能 ナツル, Senō Natsuru] is the series' main protagonist. He is a second year student of Seitetsu Gakuin High School and is the first person to be introduced in the series. He has a crush on Kaede Sakura, one of the school beauties, to the point of single-mindedness and sees other girls with indifference He is chosen as a Blue Kämpfer by the Moderators and setup as a Zauber type with power based on fire. In keeping with the rule that all Kämpfers are females, he turns into a girl upon transformation. Natsuru was given a stuff animal called a Messenger by Sakura. This stuff animal is named Harakiri Tora, meaning Disembowled Tiger. He basically tells Natsuru that he is now a Kampfer, and has to fight other Kämpfers that have different colored bracelets. When Natsuru asked him why Kämpfers had to fight, Harakiri Tora says he doesn't know. But in manga chapter 22, he learns from Mikoto that her Messenger said she was saving the world from something, but she doesn't know what.

Natsuru's meets his teammate Akane Mishima when she tries to kill him on the way to school. He manages to get away from her, but Akane comes looking for him in her normal form. She came to explain that when she transforms her personality changes, and they were on the same side and was sorry to have attacked him. In the manga once Natsuru and Akane became friends, he asked her to come shopping with him to find some female chothes to wear for when he transforms and Akane agreed to come with him. Later Natsuru went on a date with Sakura in his female form and Akane stayed close by in case he will change back into his normal form. Sakura asked if Natsuru could be her girlfriend. Natsuru excuses himself and goes the restroom wondering how to answer her, Akane had transformed asking the same thing to him. He deicides to say no, but when he goes back to find Sakura he meets Shizuku Sango, a fellow student of Seitetsu Gakuin High School, at a restaurant. She claims to have kidnapped Kaede Sakura and says she won't release her unless Natsuru and Akane fight her. They both agree to fight Shizuku in two nights at the school. Natsuru and Akane defeated Shizuku and made a truce.

After a fight with Shizuku, he exposed his Kämpfer form to other students of the school. Shizuku arranged to have him enrolled in girl's class to fulfill public curiosity in a way that diverts attentions away from Kämpfer battle. His Kämpfer form has subsequently been ranked among the Three Beauties of Seitetsu (there used to be only two) and, much to his own dismay, become subject of intense affections from Kaede Sakura (who has displayed no particular interest in his Normal form) and the female student body. He has also notice that whoever has gotten a stuff animal(which is a messenger) will become a kampfer, after the time when his childhood friend Mikoto Kondo became a kampfer after she got a stuff animal from Kaede. He is voiced by Inoue Marina in the anime.

In his male form, Natsuru is a rather tall blue-haired boy, with a slender but solid build. He has curving bangs that curved inwards from his temples, obscuring most of his forehead, and his eyes are the same color as his hair. As a Kampfer, he essentially becomes a female version of his true form: slightly shorter (but still taller than most girls of her age), more petite, very well endowed, and with longer (but basically the same) hair-style that is tied into a short know that sticks up the back of her head. His female form is generally seen wearing the school's standard uniform for female students. And being a Blue Kämpfer, his Kämpfer bracelet is on his right wrist. Natsuru in the novel and manga maintains his male voice in normal and Kämpfer form. However in the anime when Natsuru transforms his voice becomes more female.

Though he can shift into the form of a gorgeous version of himself and then vice-versa, Natsuru still retains the mentality of a male while assuming his Kämpfer form, to the point where she suffers from nosebleeds just after seeing herself with her immense bosom exposed. He is surprise when Kaede Sakura said that "I will not lose Senou to you" even though he is her when he is in his kämpfer form.