Meet Shin Hyomyung, a 26-year-old South Korean man who has refused to grow up. Hyomyung suffers from a rare affliction called Highlander syndrome that has halted the natural aging process in him.

According to Australia's, Hyomyung has yet to reach puberty and has a high-pitched voice and chubby cheeks, just like many teenage boys. Although Highlander syndrome is not yet a medically recognized term, The Metro reports that it has caused Hyomyung's body to age at a very slow rate.

Hyomyung is now famous as the Peter Pan of South Korea. Born in 1989, Hyomyung says he likes to go clubbing and drink beer with his friends. A South Korean documentary shows Hyomyung dancing and drinking at a nightclub.

The documentary also reveals that Hyomyung grew up normally until he reached his teenage years. However, he has been the same since then. He often uses an identification card for verification of his actual age, reports

Hyomyung is shown undergoing a makeover in the documentary, but it failed to make him look older. The South Korean man is about 5 feet, 3 inches tall, and still has baby-soft chubby skin. But despite his condition, Hyomyung claims he is perfectly healthly.

Richard F. Walker, a medical researcher, believes that a thorough study of the condition could possibly reveal the secret to the “biological immortality.” “If we could identify the gene and then at young adulthood, we could silence the expression of developmental inertia, find an off-switch, when you do that, there is perfect homeostasis and you are biologically immortal,” Walker said in a statement.

However, the researcher clarified that biological immortality does not mean people won't die. Other diseases and medical conditions would still have the same effect on health.