Chacha, the second offspring of the Kiseichū queen, differs from her species by emitting unique pheromones that drastically amplify human H-energy, intensifying sensitivity and arousal in those exposed. This trait caused her own kind to despise and imprison her.

Her pheromones induce multiple effects: they heighten H-energy sensitivity to extraordinary levels, described as incredible and capable of delivering unmatched pleasure, making her valuable for replenishing H-energy reserves. The resulting intense H-energy allows her temporary influence or control over affected individuals. When biting a human, she triggers "Beast Mode" by transferring concentrated pheromones, granting the recipient a temporary surge in H-energy alongside heightened speed and traits mirroring her own. Chacha also transforms her appearance to mimic humans, animals, or objects, absorbs others into her body, and senses H-energy measurements.

Naturally kind and eager to assist, Chacha’s limited grasp of human behavior occasionally yields unintended consequences. She fosters a notably flirtatious dynamic with Retto Enjō, deriving pleasure from instigating or intensifying sexual scenarios involving him and the team’s female members. Despite her origins, she allies with the protagonists against the Kiseichū threat, leveraging her unmatched H-energy amplification to support their cause. Her role bridges the conflict between species, serving as a key asset due to these capabilities.