Yumi Aiba, an 18-year-old from Kanagawa, stands 158 cm tall with measurements of 81-57-80 cm, blood type O, and a birthday on April 15. Her passion for gardening centers on flowers, driving her dream to become a floral-themed idol. This motif defines her stage presence through flower-adorned costumes, hairstyles, and performances, often intensifying in complexity over time, with a signature flower typically in her hair. She usually smiles in depictions, though seasonal variants like New Year cards may diverge. Calm by nature, she struggles with acting roles demanding anger. Beyond flowers, her gardening extends to attempted vegetable cultivation, yielding poor results due to her preference for ornamentals. This hobby spills into off-stage activities: she bakes while carving intricate chocolate roses, sometimes humming other idols’ songs. Seasonal events unveil playful quirks, like Halloween where she dons a vampire costume, jokingly threatens to bite for candy, but flushes with embarrassment if challenged, accepting sweets instead. Her social circle includes a close friendship with Nana Abe, occasionally skirting the topic of Nana’s hidden age. She collaborates across multiple idol groups: Einferia with Minami Nitta, Fumika Sagisawa, Arisu Tachibana, and Aiko Takamori; Flowery exclusively with fellow flower enthusiast Aiko Takamori; Caper Parade alongside Momoka Sakurai, Hiromi Seki, Miria Akagi, and Frederica Miyamoto; and Fiorentina with Kotoka Saionji. These alliances showcase her versatility in diverse themes and performance styles. Her growth unfolds through escalating event involvement—from 2016’s "Tsubomi" token event to 2017’s "Akikaze ni Te o Futte" and 2019’s "Mujuuryoku Shuttle"—and evolving card designs. Early Rare and Super Rare cards like "Moonlight Flower" and "Tsubomi" give way to intricate Super Super Rare variants such as "Bundled Feelings," "Piled Petals," "Sunny Summer Bouquet," and "Flower of The Night," the latter breaking her typical smile with an intense gaze. In-game, she is a Passion-type idol specializing in Dance, wielding skills with floral names or effects. Casual moments depict her picnicking or hugging cushions during everyday chats, highlighting her approachable personality and the contrast to her stage persona.