Kira's introduction involves an embarrasing public introduction by her father Ken Yukimura, the new history teacher, who comments on the fact that she had not brought a friend home despite being enrolled at Beacon Hills High School for three weeks. Presumably, this is the first time Scott notices her, and she notices him.
Soon after, Kira complains to her father about humiliating her in front of her classmates before seeminly sensing that Scott can hear what her and her father are saying, even though Scott and Stiles are on the other end of the hallway. She continues to stare at him curiously, even while Stiles drags Scott away to an empty classroom, to keep everyone from seeing him shift.
Later, she confronts the group while they are discussing their sudden hallucinations, explaining that she overheard them and that she believes they are talking about "Bardo", the tibetan word for inbetween states. She explains that in bardo you go through different stages, can be visited by wratheful and peaceful deites (wrathful deities being demons), with the final stage being death.
More Bad Than Good
Kira catches Scott at the beginning of history class, introducing herself (before remembering that he knows who she is) and saying that, because her explaination of bardo the day before was "all over the place" she did research on it and printed it all out for him. He tells her she didnt have to, but she says that it only took a couple of hours--to which he says she really didn't have to. After trying to find it in her bag, her father hands her the research and says "you forgot all the research you did for that boy you like", embarrassing her again.
When class ends and Stiles and Scott still havn't returned from "the nurse's office" (where Scott told Ken Yukimura he'd take Stiles), she decided to take their bags to them. In the hallway, though, she was caught by Malia in her coyote form. Malia corners her in a locker room, and she ends up being saved by Scott. The police and her father show up not long after, and when Ken Yukimura asks her why she wasn't headed to lunch, she said she was going to return their bags because she wanted to do something nice, because "you do something nice, you make friends..."