Shiki is a young girl with waist-length black hair, with some hair over her shoulders, and over her right eye, while she has two green hairclips preventing her hair from covering her left eye too. She has brown eyes and is perpetually with her eyes half-open. She is a B-cup who is usually hunched forward.
She wears the standard Operator uniform: a white dress shirt under a black suit with large orange stripes divided in three parts on the sides of the sleeves and another down the front flap, and also a headset.
Shiki is a Hikikomori, whom holed up in her home with only water and salted kelp that she buys through online shopping. Despite being a smart and playful girl who enjoys teasing her team mates, especially Akane, she isn’t good at dealing with people of the opposite sex, especially with men older than she.
- She likes games, water, reading, and online shopping.
- She's responsible for designing Nasu Unit’s current uniform and Operation Room.
- She was living alone holed up in her home until Kumagai scouted her.
- Out of all the operators in Border, she has the highest Trion level of 7.
- She is currently the only member of her team not to share her voice actress with another character in the anime.
- Her voice actress was also not revealed together with her teammates, being revealed only when she appeared in the anime.