She has waist-length black hair and neat, straight bangs fully covering her forehead, and her hair falls over her shoulders. She wears a school uniform consisting of an apron dress with six buttons over a white dress shirt. She also wears a thin ribbon as a bowtie and a black transparent pantyhose. She has a one-sided headset. It is unknown if she wears a uniform like operators in the main series.
She is serious and short-tempered, physically punishing Yōtarō, for risking the lives of his comrades, and Jin, for groping her. She also seems to dislike her base's leader, Tadashi Yuiga.
- "Ruka" is written with 瑠 ("precious stone, gem, lapis lazuli") and 花 ("flower"), while "Shinoda" is written with 忍 ("patience, endurance, stamina") and 田 ("rice field/paddy, field")
- She and her little brother share their surname with Masafumi Shinoda from the main series.
- She bears a striking resemblance to Haruka Ayatsuji from the main series, except with longer, black hair.
- Her school uniform looks like Ai Kitora's.