re: Why didn't Karate Kid ever carry key characters over?

Ali wasn't carried over because she made the best decision of her life and ditched that bitch arse Danielsah for a much, much better guy (UCLA football player).

Let's face it, Kumiko was never gonna move to the States and go through immigration paperwork to end up with some fig like Danielsah. She found her a good, honorable Okinawan and settled down for a comfortable life. Hell, maybe Chozen even came back and apologized, and he and Kumiko lived happily ever after. After all, he knows she riked him with his shirt off.

John and all of his classmates clearly went on to lead successful lives. Hell, while Daniel was disrespecting first class Japenese citizens and I bet they all were studying hard (and partying hard) in college like normal kids, and eventually went to law school and started a law firm together and ball out on the weekends on their yachts. While Danielsah tinkers with old cars, catches flies with chopsticks, and makes a menial living as a makeshift handyman doing odd jobs for Mr. Miyagi.

Also, I always post this awesome thread when things like this come up.