Kaede Sakura (沙倉 楓) is the primary antagonist of the series. She is one of the Three Beauties of Seitetsu, the main attraction of Natsuru Senō and the childhood friend of Shizuku Sangō. Kaede also has many admirers and Natsuru being one of them and has a large collection of stuffed Zoumotsu Animal dolls and likes to present them to her friends but those who receive the dolls, however, tend to end up becoming Kämpfer. She began to develop a crush on Kämpfer Natsuru after his Kämpfer form saved her from Kämpfer Akane Mishima at the beginning of the series, later coming under the mistaken impression that the normal Natsuru is her rival for Kämpfer Natsuru's affection and consequently becoming hostile to him, a situation not helped after a misunderstanding in a compromising situation leads her to think that Senō is cheating on his Kämpfer form.
While Kaede's usual demeanor is happy and kind, she is revealed later on in the series to have a serious, baleful side to her personality, which may be identified by her eyes becoming narrower than usual. Her split personality may be attributed to interference from the Moderators, who wish to end the truce established by Shizuku between Red and Blue Kämpfer. Hiaburi Raion (Burnt Alive Lion) elaborates that the Moderators interfered so that the victor of the revealed cosmic battle between the forces of "Red" and "Blue" may be decided, with the Kämpfer as their pawns.
Kaede is eventually revealed to possibly be involved with the appearances of the White Kämpfer and implied to be manipulating Senō. The former is confirmed later on separate occasions when White Kämpfer swear loyalty to her even though she possesses no Kämpfer bracelet. She wields both a Japanese sword and a Beretta 93R against the Blue and Red Kämpfer. Kaede's weapon skills are a force to be reckoned with in combat, since she proficiently dual wields her sword and pistol with ease against multiple Red and Blue Kämpfer. The series also implies that she knows that there are not two separate versions of Natsuru, instead one that switches gender (she personally reveals it in the anime whereas in the novel, it is her White Kämpfer who would do so). In the end of episode 9, it shows that Kaede may have a special hypnotic power, which she uses by gazing into the eyes of another person. She then utilizes this power to manipulate Natsuru to her bidding.
Oddly, the friendlier persona of Kaede has no recollection of her actions in her sinister form of consciousness, and acts as if everything is normal when questioned about her motives. The mind control from the moderators likely overwrites her current state of thinking, so that Kaede may act without remorse or regard for the Red and Blue Kämpfer. Given that Kaede's alternate personality recognizes Natsuru and company, this shows that Kaede retains information from her optimistic identity when potentially under the influence of moderators. Kaede may be hard to read since she often switches back and forth between her parallel identities at unpredictable intervals.
- In chapter 56 of the manga when Kaede regains consciousness she states she loves both the male and female versions of Natsuru Senō, yet Natsuru ultimately chooses Shizuku Sangō as a girlfriend in the manga, which ends with Natsuru and Shizuku holding hands. Alternatively, Natsuru results in choosing Akane Mishima as a partner in the light novel. In the anime, Natsuru's partner is left undecided by the end of the series, though the episode "Their Christmas ～The Entrails' Miracle～" reveals that he somehow ended up with the female Natsuru without providing any explanation.