Kirie has the appearance of a typical anime schoolgirl. She has quite dark purple hair, often tied in a ponytail, with some tips sticking out in different areas of her head and a couple of locks covering most of her forehead. She has dark, sharp purple eyes that match the color of her hair.
She is usually seen in her school uniform, with her white long-sleeved shirt tucked into a red skirt, and a red ribbon around her neck. She also wears dark brown socks with a pair of regular black school shoes. Outside of school, she usually wears T-shirts and blouses, often described as frilly.
Kirie is a fairly thin girl and has a fairly athletic body despite not being very tall.
Kirie is described as having an extremely menacing aura, which leads her to having few friends. Kirie may have earned this reputation as aggressive when she started her classes, as she was seen hitting an older man (her brother) and since then several students have been afraid to get that close to Kirie without really knowing her.
It's also implied that she is actually quite shy to the point that she can only talk to small children, as seen with Umaru's indoor mode, which has the appearance of a child. She calls Umaru's indoor mode (Komaru) "Master/Mistress" and is in service to her. When she is with Komaru we see a facet of Kirie more beautiful and helpful because she serves her teacher Komaru since he met her although she is really Umaru (Umaru Doma).
Her relationship with Komaru helps Kirie to be more social, open and to take a lot of confidence to be with Umaru and company, she even relates with Alex (Alex Tachibana) and Taihei (Taihei Doma) although at the beginning it costs her.
However, she is often violent towards her brother Takeshi Motoba, due to his occurrences and actions. Takeshi is always concerned about his sister's well-being despite his treatment of her and always tries to relate to Kirie to get back to his old relationship.
Kirie (切絵): Kiri (切) means cut, cutoff, or be sharp while E (絵) means painting, picture, sketch, or drawing.
- Kirie has written a story book for children, named Master and the Mysterious Fish. Kirie's storybook author's name is “Kirinrin”.
- Kirie has a "special ability" to remove all traces of her existence, becoming invisible.
- She has the skills of a pro swimmer, but gets quiet when people compliment her about it.
- Kirie wasn't allowed to ride a roller coaster because she didn't clear the height restriction of at least 140cm.
- She secretly has a crush on Umaru.