This wasn't Thornberry's only surprise. "There were multiple mirrors in the school, full length ones in every hallway," she said. "Men and women here are always looking in mirrors, and they're not shy about it." Large scales were on the second floor corridor of the school, free for any students to use. "Weight is tied to health and beauty here," said Thornberry. "If Koreans think you are overweight, they're not shy of telling you to your face."

Thornberry didn't have this problem, as her slim physique, blonde hair and blue eyes represented a certain stereotyped American ideal. "This teacher, she is pretty," said schoolgirl Ye Jin-Kim, 16. "Small face, big eyes, oh so pretty." Jin-Kim doesn't regard all her teachers so highly. "We had an art teacher who went to have a baby and she came back with a new nose. She looked so much better!"

Cosmetic surgery is rampant in Gumi Girls High School -- and indeed, in all of South Korea. The International Society of Aesthetic Plastic Surgeons reported that one in five South Korean women have had some form of surgery, and this number includes adolescents.

The most common procedure by far is that of the double eyelid, also known as blepharoplasty. This type of surgery creates an extra fold of skin above the eye that is visible when the eyes are open. Only around 50 percent of the East Asian population is born with a natural "double lid."

Jin Kim is planning to have eyelid surgery next year when she graduates high school. She will be joining a large number of her classmates when she does so.

"In our school most students want to have a plastic surgery," Seonghee said. "They plan to do it during their ... winter vacation." A number of her friends have already undergone this process, and she thinks it's very pretty. There is also no stigma attached. "Why would there be?" she said. "It's common to change one's face in Korea."

"Students would come back from vacation and tell me that they had gotten eyelid surgery," said Thornberry. "It was very strange, as my background predisposes me to tell them that they don't need to change anything, but they are looking for congratulations -- they want me to tell them that they look 'pretty' now."

One of the main reasons that eyelid surgery is so prevalent here is that it is considered on par with beauty treatments, not surgery. Citizens see it as so minimally invasive that they rarely take time off work or studies afterward. The practice dates back to the 19th century: In 1896, Japanese physician known as Mikamo performed the first recorded double-eyelid surgery in Japan. His motivation was to make the Japanese face "more attractive" during a time of cultural transition.

These days, an increasingly skilled workforce needs to unwind, and the Korean Pop scene provides a respite to those working 16-hour shifts. Pop singers shape the youth culture and alleviate work stress through repetitive songs and flirty short skirts. They've created a beauty physique that is adored by both sexes, and their blend of lighthearted pop and innocence has lead to their images being plastered onto everything from cereal boxes to beach towels and socks.