Lookism

Park Hyung Suk has spent 17 years of his life at the bottom of the food chain. Short, overweight, and unattractive, he was used to being bullied by his classmates and was constantly discriminated against because of his appearance. In an attempt to escape from his biggest bully, Lee Tae Sung, he decides to transfer to Seoul Jae Won High School, a vocational preparatory school known for its liberal education system and carefree students.
A few days before his transfer, Hyung Suk wakes up to find that he is no longer in his usual fat body, but in a perfect body! Tall, handsome, and beautiful, Hyung Suk has become the ideal version of himself. The only problem was that his real body was still next to him—and when one body fell asleep, he woke up in another.
Now having two very different bodies, Hyung Suk must learn to navigate his new, much more popular life at J High while also solving the mystery of where his second, almost superhuman, body came from.