Karin is a short individual that has dark grey eyes and raven-black hair that she wears in a short ponytail, with bangs that frame on both sides of her face. She usually wears her school uniform, a blue and white sailor fuku, when she's at school. Her casual outfit consists of a dark blue, long-sleeved shirt with a yellow vest, white pants, and a pair of red sneakers with black highlights and white soles.
Compared to her soft-spoken sister, Yuzu, Karin is the more authoritative of the two. Karin's tough exterior results from her mother's death; because she could not be useful around the house like Yuzu, she resolved never to cry so that she would not burden her family with her personal troubles. As a result, Karin appears to be the most harden and least emotional out of the two resulting in her not being affected by most events that would more or less bring tears to Yuzu's eyes. Despite these obvious differences, both girls remain close and share an equal concern for their older brother when Ichigo appears stressed or when he disappears for long periods of time. During these times, despite her own worries, Karin will reassure her sister, being there for her.
Karin is a sensible person and but is not above kicking her father in the head when she thinks he's acting unreasonable, which is generally a lot of the time. Despite this, she is still helpful around the clinic. Both she and Yuzu helping out their father as nurses when they can. She initially claims that she believes spirits do not exist; however, she can see them just as well as her brother Ichigo can. She can also sense them from great distances, which usually manifests as a headache.