As a human, Kanna appears as a young girl with long white hair (with purple tips in the anime) that splits into two ponytails with three large beads. She has four horns (one facing up and down on each side) and a long thin tail that ends in a puffy ball, similar to that of a poodle. She can freely hide both the horns and tail to blend in with humans, and can also manifest her wings in human form to fly without fully transforming. Normally, she wears a thigh-length dress similar to clothes traditionally worn by the Ainu people, leading her to be called GothLoli.
Her dragon form has a beaked mouth, is covered in fur or feathers, has a pair of feathered wings, and her tail is longer and thicker in comparison to her humanoid form's.
Kanna appears stoic, rarely changing her facial expression or raising her voice, but is actually very emotional. While young by dragon standards, she is more mature than her apparent age would suggest, and when angry she can be foul-mouthed and rude. Due to her young age, Kanna enjoys frequent naps and has a ravenous appetite, frequently snacking and eating any animal she can fit into her mouth, including insects, crabs, and fish.
Tohru notes that she is mischevious and enjoys playing pranks, though this was in an ultimately futile effort to obtain her parents' attention. While this tendency lessens over time, she's not above using her cuteness or faking sadness to manipulate others' emotions. Initially jealous of Kobayashi's relationship with Tohru, she has latched onto the human woman as a surrogate mother - to the point of calling herself Kanna Kobayashi - and views Tohru as an older sister. She also has romantic feelings towards Saikawa, expressing a desire for a relationship similar to what Kobayashi and Tohru have.
She is the second dragon in the series to join Tohru in the human world. She was exiled by her parents for excessive pranks until she learned her lesson but decided to follow Tohru to the Human world and ended up living with Kobayashi, who she considers to be her mother.
- Kanna is based off of the Ainu Kamuy (goddess) of thunder and lightning, Kanna Kamuy. Her cover story at school that she comes from Ushishir is a reference to this.
- Her personality is somewhat a resemblance to Renge Miyauchi from Non Non Biyori. Both are described as very smart, their expressions almost never change, and they love to do random things.
- She "recharges" by "plugging" her tail into an electrical outlet.
- She attends Oborozuka Elementary, along with Shouta and Saikawa.