Jang Pan-soo,
a hardened gangster, finds his life drastically altered when a freak accident swaps his consciousness with that of Dong-hyun, a timid high school student.
Trapped in a younger, weaker body, Pan-soo must adapt to the unfamiliar world of school,
facing bullies and navigating the complexities of teenage life.
He discovers that Oh Hyun-jung, a classmate, is his estranged daughter, and he takes it upon himself to protect her, training her to defend herself.
This leads to a rekindled connection with her mother, his former love, Oh Mi-sun.
Meanwhile, Pan-soo’s rival, Boss Yang, seizes the opportunity to frame him for embezzlement, threatening his reputation and life. With the help of his loyal subordinate, Man-chul, and the bewildered Dong-hyun, Pan-soo works to clear his name and expose the conspiracy.
As they navigate this bizarre situation, Pan-soo learns valuable lessons about family, love, and redemption. When Dong-hyun wakes up in Pan-soo’s body, the two must work together to clear Pan-soo’s name. After a final accident that returns them to their original bodies, Pan-soo chooses a new path, embracing his family and leaving his gangster life behind.
