Kiyomi Mikawa attends Golden Star Academy, known for academic excellence and a reserved demeanor. Her modest personality and studious nature earn her the label "brain," highlighting her intellectual role. Despite her outwardly shy disposition, she possesses a strong sense of heroism that defines her actions once her secret identity activates.

Recruited as one of five warriors serving the goddess Aphrodite, she transforms into Venus Blue. This transformation is marked by a blue Venus symbol on her right breast, serving as both an identifier and the source of her supernatural abilities. Her role within the Venus 5 team involves defending Earth against the Inma Empire, an organization seeking to impose a reign of perversion and lust under Necros. Her combat duties frequently entail confronting the empire's agents, who often employ grotesque, tentacled threats.

Kiyomi shares a close bond with Hikari Misono (Venus Pink), considering her a best friend and relying on their partnership in daily school life and during missions. This relationship forms a foundational aspect of her team involvement, as their camaraderie supports their efforts against the Inma Empire. Her journey from quiet student to determined warrior illustrates her core duality: maintaining her studious persona while embracing her responsibilities as Venus Blue.