Weak hero

Eun. Gotak was a taekwondo athlete, but after a serious fight with Sung-jae, he was injured and quit the sport forever. He used to be incredibly strong. He sometimes doesn't smile, is stubborn and hot-tempered, but greatly values ​​his friends and his handsome best friend, Baku. Shi Eun is a very smart, cold guy who almost never smiles. He has a heavy and sad look. He is always loyal to his friends. In fights, he tries to win not with his fists, but with objects, although he can fight with his hands. Jun-tae is a sweet, slightly cowardly guy who doesn't know how to fight, but has an incredibly kind heart. Baek Jin is a cold, calm, cunning, tough, and confident leader. He manages people perfectly and never shows weakness. He uses any means necessary to achieve his goals. Do Sung-mok is a guy from Baek Jin's group. Cold, withdrawn, tough, and aggressive. He speaks little and is secretive. He is brutal in fights. Baek Dong-ha is a member of Baek Jin's gang, his right-hand man. He is a tough, aggressive, hot-tempered, and rude delinquent. Hyo Man is the main bully at Eunjang High School, aggressive and arrogant, bullying the weak, feeling like he owns them, and keeping others in fear with his gang.
An MMA legend, hospitalized, breathes his last. At the same time, a weak girl (Soo Na), constantly bullied and beaten at school or on the street, gets into a car accident, or is beaten within an inch of her life. At the very moment their hearts simultaneously stop beating, the soul of the old athlete awakens within the girl's body.

You're a legend, a professional boxer and MMA athlete, but your time has come, and you die in the hospital of old age. Meanwhile, a young girl, bullied at school, dies on the street of cardiac arrest, unable to withstand yet another round of bullying. But your soul is transferred into the body of this young girl, and now you continue your life in her body...