Thirty-four years after being defeated by Daniel LaRusso in the 1984 All-Valley Karate Tournament at the end of The Karate Kid (1984), Johnny Lawrence suffers from alcoholism and depression. He works as a part-time handyman and lives in an apartment in Reseda, Los Angeles, having fallen far from his wealthy lifestyle in Encino. He has an estranged son named Robby, from a previous relationship, whom he has abandoned. In contrast, Daniel is now the owner of a successful car dealership and is married to co-owner Amanda with whom he has two children: Sam and Anthony. However, Daniel often struggles to meaningfully connect with his children especially after his friend and mentor Mr. Miyagi passed away prior to the series' beginning.

stars Viola Davis as Annalise Keating, a defense attorney and law professor at a prestigious Philadelphia university, who, along with five of her students, becomes involved in a complex murder plot.