"She is am amazing student," McMillin said. "There was only one time when she missed one math problem, other than that Yoon never missed a problem in any of her math and science exams and quizzes."
But the La Crescenta teen doesn't wear her ambitions and accomplishments on her sleeve.
"She tries not to hurt anyone's feelings," said Jisun Lee, Yoon's older sister. "Although she is the youngest in the family, she has deeper thoughts and a warmer heart than anyone else."
Always doing above and beyond what was required, Yoon did every extra credit offered.
McMillin said that if she missed a homework problem, the teen asked for clarification on her mistakes.
"She wasn't picking for points. it was more because she needed to clarify it for herself. She is not obsessed with grades, she is just dedicated like that. You just knew she wasn't going to settle for less." McMillin said.
Often times Yoon said she would stay up all night studying and doing homework.
The most difficult distraction for her to turn down was talking with to her friends during her recess breaks. She said she would instead choose to stay in the classroom and study for those extra 15 minutes. which would give her an edge in her studies.
Yoon said her secret to her academic success is that even when she wats to play with her friends studying is better in the long run.
"When I study and get all the concepts, I feel that I've achieved something," said, Yoon who was born and raised in South Korea.
At 8-years-old her family migrated to the U.S. for better job opportunities.
Now her parents run a small Korean hospital for seniors located in Korea Town in Los Angeles.
Like her parents she too wants to work in the medical field and become a doctor.
To get a head start with high school, Yoon is currently taking a biology class this summer at her future high school, Crescenta Valley High.
According to Jisun, Yoon already started studying the human bones. "I am so proud of her and so happy to have her as my sister," she said.
But Yoon's impressive resume doesn't end in academics. She was involved in the Associated Student Body at Rosemont and volunteered community service hours through school clubs where she worked the jog-a-thons, the L.A. Marathon and donating teddy bears to mothers in prison.
When Yoon feels discouraged she reminds herself of her favorite quote by Thomas A. Edison as a source of inspiration: "Genius is one percent inspiration and ninety-nice percent perspiration."
This is the model Yoon said she lives up to everyday. "It makes me feel like nothing is impossible," she said.