Daniel LaRusso, a teenager, relocates with his mother from Newark, New Jersey, to Reseda, Los Angeles, California. Struggling to fit in his new environment, he becomes the target of bullies from the local karate dojo, Cobra Kai. After a beach party where he meets and forms a budding romance with Ali Mills—a high school cheerleader—the bullies, led by Johnny Lawrence, who is Ali’s ex-boyfriend, escalate their torment of Daniel. Following one particularly brutal encounter, the elderly and seemingly mild-mannered handyman, Mr. Miyagi, intervenes and reveals his mastery of karate by defending Daniel from the attackers.

Recognizing Daniel's need for help, Mr. Miyagi agrees to teach him karate. Through unconventional methods, he imparts not only the physical skills necessary for self-defense but also valuable life lessons about respect, balance, and the importance of avoiding conflict when possible. As Daniel learns and grows under Mr. Miyagi's tutelage, he prepares to face his adversaries in an upcoming karate tournament, which will test his courage, skill, and newly acquired understanding of martial arts philosophy. Meanwhile, Daniel’s relationship with Ali deepens, and his confrontations with Johnny highlight the contrast between two starkly different approaches to martial arts and life itself.