The Karate Kid.

New Jersey teen Daniel LaRusso moves to Los Angeles with his mother, and soon strikes up a relationship with Ali. He quickly finds himself the target of bullying by a group of thugs, led by Ali's ex-boyfriend Johnny, who study karate at the Cobra Kai dojo under ruthless sensei John Kreese. Fortunately, Daniel befriends Mr. Miyagi, an unassuming repairman who just happens to be a martial arts master himself. Miyagi takes Daniel under his wing, training him in a more compassionate form of karate for self-defense and, later, preparing him to compete against the brutal Cobra Kai.