Kaede Sakura is a central figure in the Kämpfer narrative, recognized as one of the Three Beauties of Seitetsu High School alongside Shizuku Sangō and the female form of Natsuru Senō. She is the childhood friend of Shizuku and the object of Natsuru’s long-standing affection. Her background reveals that she lives alone, as her parents are diplomats working overseas. A defining and peculiar aspect of her character is her passionate collection of Zoumotsu Animal dolls, which are stuffed animals designed to look as though they have died in brutal ways; she finds these grotesque dolls genuinely beautiful and often gives them to friends, an act that inadvertently causes the recipients to be chosen as Kämpfer.

On the surface, Kaede projects a personality that is happy, kind, and popular, endearing her to much of the student body. However, this persona is a facade that conceals a far more serious and sinister side. As the story progresses, it is revealed that she is the primary antagonist, whose actions are heavily influenced by the Moderators, extradimensional beings using the Kämpfer battles as a proxy war. This interference has fractured her psyche, creating two distinct identities. The friendly, public-facing Kaede has no memory of the malicious actions performed by her other self, a controlled and baleful personality that manipulates events from behind the scenes.

Her motivations are complex and driven by this dual nature. The kind persona develops a strong romantic infatuation with Natsuru’s female Kämpfer form after being rescued by her, leading her to mistakenly view the male Natsuru as a rival for her affections. Her orientation is heavily implied to be lesbian, as she not only favors the female Natsuru but is also shown to have a harem of female admirers who act as her girlfriends. In contrast, the malevolent persona, acting as the Moderators’ enforcer, is driven to end the truce between the Red and Blue Kämpfer and sow chaos, viewing all Kämpfer as mere pawns in a larger game.

In her role within the story, Kaede is the mastermind behind the appearance of the White Kämpfer, to whom she commands absolute loyalty. Unlike normal Kämpfer, she does not possess a transformation bracelet but can still fight with extraordinary proficiency. Her key relationships are defined by this conflict. She is a beloved friend to Shizuku but also a manipulative foe to Natsuru and the other Kämpfer. In one of her most notable acts, she uses a special hypnotic power to mind-control Natsuru to do her bidding. Her abilities in combat are formidable; she dual-wields a Japanese sword and a Beretta 93R pistol, demonstrating skills that allow her to easily hold her own against multiple opponents at once.

Regarding her development, the series explores the tragic nature of her condition as a puppet of higher forces. While she functions as the main antagonist, it is suggested that her actions are not entirely her own, with the Moderators overriding her consciousness to use her as their earthly agent. The conclusion of her arc varies across different versions of the story. In the manga, after she regains consciousness, she confesses to loving both the male and female versions of Natsuru, though Natsuru ultimately chooses to be with Shizuku in the end. The light novel concludes with Natsuru choosing Akane Mishima instead. The anime leaves the romantic conclusion unresolved, though it strongly implies her manipulative and powerful nature as the central antagonist.