Kirin has reddish-brown eyes and dark green hair, which she normally keeps tied in pigtails. She often wears collared dresses or pinafores, as well as white balloon shorts. She is often seen carrying around a large, stuffed toy giraffe, a beloved possession.
She is very friendly and sweet. She likes to play house and becomes friends with Inomata Maria, who returns to the daycare repeatedly to meet her, and is happy to have an older sister to play with. She also takes care of the baby girl, Sawatori Midori, behaving like an older sister herself.
She is smart and eloquent, often clashing with Taka over differences in opinion, such as who is a better friend to Kotarou or the game for the day. Although this personality clash seems to suggest their friendship is unsteady, like when she once tattles on Taka for upsetting Kotarou, the two always put aside their differences and often come together when they agree. Taka is also the only child who provokes Kirin unnecessarily, with Taka arguing that witches and magic do not exist, resulting in retaliation from Kirin as she goes to dangerous lengths to prove him wrong. She also calls Taka out as a "bully", and they do not like each other mually which they do in fact.Kirin cries with big watery eyes and red cheeks when she fails at doing something or even when someone dislikes a favourite thing or person of hers. She has a lot of ideas and is helpful to others.
She is the only child of Kumatsuka Satoru and Kumatsuka Yayoi. Kirin is well-loved by her parents, especially Satoru, who is overly protective of his daughter. She claims that her mother, Yayoi, is her "favourite person in the world" in front of Satoru previously.
- Her favourite toy is a stuffed giraffe, relating to her name which means giraffe.
- Her favourite food is her mum's pickled radish.
- Kirin's favorite TV show is a magical girl anime called "Petits Pois," where two girls use magic to fuse into an adult superhero.
- In Taka's "Ranger Five" game, she is Ranger Pink, which she subsequently stops playing to "become a witch" instead.
- Kirin is voiced by Ayana Taketatsu on the drama CD.