
If you haven't run across it yet, the basic premise is that it follows the lives of the characters from The Karate Kid thirty years later. Daniel is now a car salesman who trades on his high-school trophies in his advertising ("We're chopping prices! We kick the competition!"). Johnny is a handyman who loses his job and decides to re-open the Cobra Kai karate dojo. The series is mostly divided into two separate threads, with one focusing on these two adults who should be friends but can't get over their high-school rivalry, and the other focusing on the teenagers they both begin to teach (Johnny in an attempt at earning money first, but then later to better both his own life and the lives of the kids he teaches; Daniel in an attempt to show up Johnny and continue their rivalry).
There's lots of melodrama. High school relationship stuff like who kissed who. Questions of loyalty, like when Johnny's own son decides to train with Daniel instead. The competing schools facing each other in the All Valley Karate Tournament. There's also the original cast of Ralph Macchio, William Zabka, and others.
But most importantly, it's just very well written. The characters are believable as middle-aged men who are still fixated on high school, and the kids are never so zany as to defy belief (This is not Saved By the Bell). Characters show real growth and change.
If you've been giving this one a pass I'd strongly recommend you check out an episode or two. The first two seasons are on Netflix now, and the third season should release sometime in 2021 (filming completed last year, but the pandemic pushed everything back).