Champion (2018)

The film tells the story of the adopted Mark (Ma Dong-seok) who was a former arm wrestler but now works as a bouncer. He goes to South Korea for a competition to search for his mother who gave him up for adoption as a child. With help of his friend, Jin-ki (Kwon Yul), Mark finds his real family, only to learn that his mother had died. He then meets his step-sister and her family whom he never knew. Through his mother's emails that he came to read he came to know what it meant to feel her pain of abandoning him. He later wins the national tournament against his opponents and in the end, defeats the opponent named Punch (Kyu-Ho Lee) in the final.