One of the main characters of Love Live! Sunshine!!. She frightens easily (and tends to emit a distinctive "pigii!" shriek), but loves school idols and always dreamed of becoming one. Ruby is the shy younger sister of Kurosawa Dia, and a close friend with Kunikida Hanamaru.
Ruby is a member of the Aqours sub-unit CYaRon!, alongside Takami Chika and Watanabe You.
She has aqua eyes and red two side up.
Voiced by Furihata Ai.