Kyōko Umekōji attends Seirei Private High School, advancing from student council vice-president to president. Her elite upbringing cultivated a fashion sense widely admired by peers. She embodies a consistently ladylike and mature demeanor, prioritizing grace and authenticity in all situations. A core belief drives her: remaining true to oneself in any role, rejecting impersonation.

Within Aikatsu Planet!, Kyōko transforms into the avatar "Beat." Beat's dramatic look features long hair, black on the right and electric pink on the left, with sharp lime green eyes—a stark contrast to Kyōko's shoulder-length black hair and calm expression. Beat favors the Bloody Rock Dressia, a rock-themed outfit with wing-shaped speakers. Its card skill activates against opponents above level 6, boosting her own level.

Her personas differ linguistically: Kyōko uses formal speech ("watashi") and honorifics, while Beat adopts "atashi" and drops honorifics. Despite this shift, both identities adhere to her principle of authenticity, never feeling like impersonations.

Kyōko mentors protagonist Mao Otoha (avatar "Hana"), supporting Mao's journey as they collectively strive to become top idols. They collaborate in the unit Kira-Pika Tune and perform the Starry Planet opening theme "Bloomy＊Smile."

A haunted house visit revealed unexpected vulnerability; extreme fear required comfort from an actor, contrasting her usual composure. She enjoys hamburgers, carbonated drinks, and music.

In the film *Gekijō-ban Aikatsu Planet!*, Kyōko/Beat participates in the "Gratitude Festival." This series of diverse performances—including bands and musicals—showcases her adaptability and dedication to connecting with fans.