Riina has heterochromatic eyes, one dark pink, one green. Her long platinum hair is worn in a spiraling ponytail decorated with a red oni mask, and two black bands, each with a sakura flower. Her thick bangs and curling forelocks frame her face.
Her attire conists of a white ruffled blouse worn beneah a black and white sailor fuku jacket that is opened to expose her navel and white thong straps. She also wears a loose red tie, red mini-skirt, a single black finger-less glove, and brown stockings with wooden sandals.
In the anime her attire's colors are darkened while her sandals gain a "modern" design.
- Her birthday is April 4th.
- Her blood type is A.
- She is one of the only girls with heterochromia (two-colored) eyes. The other being Misa Nanase.
- Both girls come from the Subculture Party.