Given the question: Build a movie plot around this: What does the main character want to prove he is not? A coward
The answer is:
The film revolves around Chang Ka-pil (Lee Moon-sik) in his 40s, who leads an ordinary life with his adorable wife and their 17-year-old daughter, Dami (Kim So-eun). He faces a crisis when his daughter is sexually assaulted by a high school boxing star from a rich, well-connected family and he finds no help from the school or police authorities.To prove that he is not a coward and will do anything for his family, he decides to take revenge and physically beat up his daughter's tormentor. For the seemingly impossible task, he asks Go Seung-suk (Lee Joon-gi), a rebellious high school student with talent for fighting, to train him.