Ruka Ichijō is a third-year student at Marehoshi Private Girls' Academy's main branch, where she confidently serves as president of the school's idol club. She performs as a member of the unit Stellamaris alongside classmates Aone Shikimiya and Sango Misaki. Ruka maintains a cool, calm composure, assured in her abilities, and commits to rigorous daily practice to uphold her skills.

Her striking appearance features silver hair styled with short back layers and a ruffled dark blue accessory, showcasing thick, uneven bangs and chest-length forelocks. She possesses distinctive purple eyes accentuated by thick lashes. Casually, she favors relaxed, oversized clothing in blue and black tones. Her idol outfit utilizes dark blue fabric with pale blue accents, including a three-layered ruffled tutu and a prominent light blue ribbon attached at the back. The design incorporates an exposed mid-torso secured by buckled straps, white lace chest coverage, and mismatched legwear—a black stocking on the right leg contrasting with full black fabric coverage on the left. Accessories include a gem-adorned hair piece and a ruffled black choker.

Ruka prefers Asian tea and harbors a dislike for fortune-telling and omikuji (fortune slips). Her surname, Ichijō, translates to "one article," while her given name, Ruka, combines the characters for "lapis lazuli" and "summer."