This 2006 film is based on a Japanese manga called Kanna-San, Daiseikou Desu. Here is a summary from crunchyroll, since you are so curious:
"Hanna is a lip sync vocalist for Ammy, the famous Korean pop singer.
Even though she is always ignored because of her appearance, she has been a bright and lighthearted girl until Ammy humiliates her in front of Sang-jun, her secret love.
At last she makes a decision of a lifetime to have plastic surgery all over her body. Will her unrequited love be returned?"
If anyone has seen this, please give us a review in the comments!