Daniel LaRusso moves to Los Angeles with his mother, Lucille, and soon strikes up a relationship with Ali. He quickly finds himself the target of bullying by a group of high school students, 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.

Summoned by his dying father, Miyagi returns to his homeland of Okinawa, with Daniel, after a 40-year exile. There he must confront Yukie, the love of his youth, and Sato, his former best friend turned vengeful rival. Sato is bent on a fight to the death, even if it means the destruction of their village. Daniel finds his own love in Yukia's niece, Kumiko, and his own enemy in Sato's nephew, the vicious Chozen. Now, far away from the tournaments, cheering crowds and safety of home, Daniel will face his greatest challenge ever when the cost of honor is life itself.

Despondent over the closing of his karate school, Cobra Kai teacher John Kreese joins a ruthless businessman and martial artist to get revenge on Daniel and Mr. Miyagi.

Mr. Miyagi decides to take Julie, a troubled teenager, under his wing after he learns that she blames herself for her parents' demise and struggles to adjust with her grandmother and fellow pupils.

After a family tragedy, kung fu prodigy Li Fong is uprooted from his home in Beijing and forced to move to New York City with his mother. When a new friend needs his help, Li enters a karate competition – but his skills alone aren't enough. Li's kung fu teacher Mr. Han enlists original Karate Kid Daniel LaRusso for help, and Li learns a new way to fight, merging their two styles into one for the ultimate martial arts showdown.