Keiko Kamikita pilots the Zambase, a component vehicle of the super robot Zambot 3. A 14-year-old survivor from the planet Beal, she belongs to the Kamikita family now settled on Earth. She defends Earth alongside teammates Kappei Jin and Uchūta Kamie against the Gaizok and their Mecha Boosts.

Her grandfather, Heizaemon Kamikita, commands the King Beal spacecraft. Her mother, Yumiko Kamikita, is of North American descent. Yumiko raised Keiko near Las Vegas with a Wild West upbringing, teaching her horseback riding, archery, and firearms handling; these skills shape Keiko's character.

Keiko possesses strong convictions and a willingness to fight, sometimes attempting to pilot even when injured. Though less overtly aggressive than her male teammates, her dedication to confronting Gaizok is unwavering. She shows emotional vulnerability, especially in response to civilian hostility toward her family. A defining combat moment features her frequently quoted line: "Please transform, and don't make a girl say 'please!'"

Her story concludes in the final battle, where she and Uchūta Kamie execute a joint suicide attack against Gaizok forces. This act results in their deaths, leaving Kappei Jin as the Zambot 3 team's sole survivor.

In expanded media, a non-canonical android replica of Keiko appears in "The Knights of the Multiverse." Created by the antagonist L.O.S.R. to manipulate her mother, Yumiko, this android initially possesses Keiko's base personality. It develops genuine emotions and bonds, eventually defecting to join the heroic Knights. Piloting mecha like God Sigma and Might Kaiser, the android grapples with identity issues stemming from its artificial nature, exploring themes of self-worth and relationships with its creator and the original Keiko, whom it views as an older sister.