I don't really think she had a plastic surgery, there's no much significant difference in her nose, and as for the eyelids the japanese makeup artists have this sticker-like thing that they apply to the eyes to create a fake eyelid effect. Her lips didn't change either, she was smiling throughout the entire video and so her lips appeared thinner. Regardelss of whether she did or not, I still like her! I think she's gonna be a great international pop star one day
Nose job? Hardly likely. It looks the same to me, plus having a nose job can greatly effect your singing voice and tone. She doesn't sound much different now than she does here. As for anything else... doesn't look like it to me, but who cares? Does it change who she is as a person or an entertainer?