Miguel Diaz is one of the main characters in Cobra Kai. Miguel had a huge rivalry with Robby Keene because Robby stole Miguel's Girlfriend. They left each other alone until the All valley tournament. Miguel won and they were fine, until there was a school fight.  When Robby and Miguel were fighting, Robby kicked Miguel off the second story of the school which caused Miguel to go into a coma.

Robby is Miguels Arch nemisis and also one of the main characters in Cobra Kai. When Robby put Miguel in the hospital, Robby was on the run so he wouldn't go to juvie.  He ran for days, but still ended up going to juvie. After Robby got out, hestarted to go to Cobra Kai.  He ended up becoming a student after saying he would never join Cobra Kai.

Hawk is a kid with a deformed lip who was bullied in school for his lip. This was until Miguel fought Kyler, his bully. This made Hawk and many others want to join cobra kai. When Hawk joined, he got made fun of by the Sensei, and decided to flip the script. He got a Mohawk and started to have a lot of confidence which got him the prettiest girl in the school.

Johnny is the main character in Cobra kai, who had a rivalry with Daniel LaRusso. He was the best student of all time that attended Cobra Kai. He became the Sensei and taught his students to be tough in order to survive  in the world from bullies. 

Daniel is the other main character of Karate Kid and had a rivalry with Johnny Lawrence.  In the Karate Kid, Daniel  moved to LA and didn't understand why. He thought his mom  was only thinking about herself, but she was doing it for him. He soon met Mr Miyagi, who was a Karate master. He became a two-time All Valley champion and stopped Karate. When Daniel heard about Johnny Lawrence reopening Cobra Kai, he also  reopened Miyagi-do to try and defeat Cobra Kai.

Sam is one of the main characters in cobra kai and is the daughter of Daniel LaRusso. She dated Robby and Miguel, which caused their rivalry. Sam didn't want to go back into karate but karate gave her life structure. She also found both of her boyfriends doing karate.  Sam also had a rival herself, Tory Nichols, who was Robby's ex.  Their rivalry started with Robby, but they ended up hating each other.

Tory is a huge character in Cobra Kai, she dated Robby and Miguel.  She started a fight at her school, which caused Miguel to break his back and go into a coma.  Tory uses the lessons that she was taught from Cobra Kai to fight the people that messes with her.

John Kreese is the founder of Cobra Kai, and has a rivalry with Daniel LaRusso.  John Kreese taught Johnny Lawrence how to fight. John is in  jail for something he didn't do. He was accused of assault and was sent to years in prison. John faked his death just so he could get out of jail and see what has happening with his dojo. 

Silver is John Kreeses old friend from Vietnam . Terry framed John and took over Cobra Kai.  It was Terry Silver who framed Kreese. Silver got the grandchild of master Kim Sung Yung. He did that to get his students stronger for the Saiki Taiki, the karate tournament. 

Demetri is in Miyagi-Do Karate, and had a rivalry with Hawk. Demetri is a nerd and went to Miyagi-do to fight back to all the kids that used to bully him. When Demetri was in the school fight, Hawk wanted to kill Demetri, but Demetri was able to counter and defeat Hawk.

Kenny got bullied in school so he took lessons at Cobra Kai to get stronger. He followed Robby Keene so he could fight back against the kids that bullied him. Kenny has started to get stronger and is now one of the stronger members of Kobra Kai.

Chozen was a character in Karate Kid 2 who almost killed Daniel back in Okinawa because of a girl. But in later seasons of Kobra Kai, he helpsDaniel take down Silver. Chozen also is a karate assassin who uses swords to kill his enemys at all cost. He is paid by rich people to get rid of others that stand in their way