Kokoa Shuzen is the younger half-sister of Moka Akashiya, sister of Karua Shuzen and stepsister of Akua Shuzen. Bearing a similar appearance to Moka with her green eyes, except for her orange hair and her "uncool" vampire attitude, she arrives as a first-year student at Yokai Academy during the second serialization and anime adaptation. Like her sister, Kokoa is also a vampire, but her powers are not sealed and does not carry the same level of supernatural strength that Moka possesses. To compensate for it, she has a pet bat named Kou that can transform into a variety of weapons and wields it with enough strength to make herself formidable.

Kokoa despises Moka for sealing away her inner personality, whom she adores and loves. Before Moka left to study at the academy and prior to her receiving the rosario, the sisters often clashed with one another, although Kokoa could never defeat Moka in a duel. She constantly attacks Moka, in hopes of drawing out the "Inner Moka", and feels angry that Tsukune has the ability to unlock Moka's true nature and begrudgingly accepts the presence of her sealed sister; though this softens to simply accepting both Mokas as her sister. Unlike Moka, Kokoa harbors a deep-seated fear of their older sister Kalua Shuzen. Known as the kindest amongst their family, Kalua continuously babies Kokoa and has a "smile of an angel", something Kokoa is frightened of as she is somewhat insane.

As a parallel to her sisters, Kokoa's name may be an intended pun on the word "cocoa".