Kana is a disobedient "bad girl" who develops a crush on Shinichi. She is attracted to him because of his sensitive personality, and because she can sense something "different" about him.

Spoiler

In reality, Kana has an unexplained psychic ability to sense parasites. However, her senses are not as fine-tuned as those of the parasites themselves, and she cannot tell whether she is sensing the presence of Shinichi or of a normal parasite, putting her in considerable danger.

(Source: Wikipedia)