Park Hyung Suk has spent all 17 years of his life at the bottom of the social ladder. Short, overweight, and unattractive, he is accustomed to being tormented by his classmates and facing constant discrimination because of his appearance. Hoping to get away from his worst bully, Lee Tae Sung, he decides to transfer to Seoul's Jae Won High School, a vocational school known for its relaxed policies and carefree student body.
Just a few days before his transfer, Hyung Suk wakes up to discover he is no longer in his usual chubby body. Instead, he now possesses a perfect physique—tall, handsome, and well-toned—the ideal version of himself. The catch is that his original body is still lying next to him, and whenever one body falls asleep, he wakes up in the other.
Now in possession of two wildly different bodies, Hyung Suk must learn to handle his newfound popularity at J High while also uncovering the mystery behind where his second, almost superhuman body came from.