Takeko Ooyama emerges as the temporary female incarnation of Takeru Ooyama after he accidentally activates Shiria Ootsuka’s Maken during a beach excursion to a southern island. This unintended transformation occurs while Takeru trains to master his own Maken abilities. Initially embracing the experience, Takeko engages in lighthearted play with Haruko Amaya and female classmates. Unforeseen complications soon arise, however, revealing the transformation’s less positive aspects.

Takeko embodies Takeru’s core personality: his perverted inclinations and clumsiness persist, frequently triggering accidental comedic mishaps or compromising scenarios. Takeru’s traumatic past—witnessing his mother’s death during a duel—shapes Takeko’s behavior, manifesting as a refusal to fight women and a "white knight" impulse to intervene in female conflicts. This trauma historically fueled Takeru’s protective instincts and impulsiveness, though he later overcame his aversion to fighting women after a confrontation with Tesshin Kushiya, recognizing it as weakness.

Takeru’s Maken abilities, "Overblow"—which disrupts opponents by overloading their Element—and the latent "Blood Pointer"—absorbing Element through bites to convert emotions into power—remain inherent to Takeko’s existence but go unexpressed in this form. The transformation proves temporary, leaving Takeru’s overarching character journey intact. This includes reconciling with his father and uncle over his mother’s death and navigating romantic entanglements with multiple female admirers.

Takeko’s existence is confined to this single incident within an OVA. The scenario functions as a self-contained comedic episode, exerting no lasting impact on Takeru’s abilities, relationships, or subsequent series developments.