Daniel (Ralph Macchio) moves to Southern California with his mother, Lucille (Randee Heller), but quickly finds himself the target of a group of bullies who study karate at the Cobra Kai dojo. Fortunately, Daniel befriends Mr. Miyagi (Noriyuki “Pat” Morita), 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 and preparing him to compete against the brutal Cobra Kai.
Workaholic Howard Langston (Arnold Schwarzenegger) wants to make things up to his son, Jamie (Jake Lloyd), and wife, Liz (Rita Wilson). He promises to get Jamie the hottest toy of the season, Turbo-Man — even though it’s Christmas Eve and the toy is practically sold out. As Langston hunts down the elusive gift, he runs into mailman Myron (Sinbad), another father on the same quest. With the clock winding down, Langston’s moral code is tested as he starts to learn the real meaning of Christmas.
In New York, mysterious radioactive ooze has mutated four sewer turtles into talking, upright-walking, crime-fighting ninjas. The intrepid heroes Michelangelo (Robbie Rist), Donatello (Corey Feldman), Raphael (Josh Pais) and Leonardo (Brian Tochi) are trained in the Ninjutsu arts by their rat sensei, Splinter. When a villainous rogue ninja, who is a former pupil of Splinter, arrives and spreads lawlessness throughout the city, it’s up to the plucky turtles to stop him.