My Fake Wife Could Kill Me With One Move

The richest man in the city has a son who spends his time on women and parties, and the father is willing to bring in someone from outside the family to deal with it. A sanda coach says in front of him that if the son were her husband she would have him behaving after one punch. The father hires her on the spot as his daughter-in-law. She backs the son down by force and takes over his money. He has more to him than the reputation he carries, and the coach has been holding things back as well. She knows wine and horses and can drive a race car, and she gets him out of danger several times, and somewhere in all that he starts wanting her for real. His first love turns up, the relatives who want a share of the family money make their moves, and the two of them handle it together. When the coach decides the job is done and gets ready to leave, it comes out at a charity dinner that the marriage was never registered.