Miguel and Sam are excited about attending the junior prom until another couple unexpectedly shows up. Terry lures Johnny to a familiar location.
Stingray is having breakfast where he has an argument with his neighbor Greg. He is upset with what he's been doing since he moved to his sister's house but he reminds him that he is on probation but Stingray says he's off probation. He tells him he needs to get ready for training. Greg angers Stingray saying that his training isn't kung fu but it's Cobra Kai and calls him "stinkray" and threatens him.
At the Cobra Kai dojo, Kyler explains his plans for the prom and Robby asks Tory if she's going but she isn't keen on it. Kreese and Silver teach the students their own version about balance how to throw their opponents off. Robby and Tory spar and tells him to go and changes her mind, saying she can go with him. Sensei Silver hears the conversation and tells the two they need to go in style. Stingray arrives at the dojo but Kreese insults him in front of the class and orders him to leave the dojo.
The LaRusso's are having dinner when the Diaz's come over. Louie tells Johnny about the biker gang and doesn't hang out with them anymore. The Diaz's and LaRusso's take pictures with Miguel and Sam before the prom, cherishing the moment. The two are happy they get the night with each other without karate.
When Johnny and Carmen go home, Shannon Keene tells Johnny where he tells that Terry Silver gave Robby a car to go to the prom. She shows him money and that she gave him and offered to help her and adds that he needs to deal with Silver.
Eli and Demetri are at prom where Eli says that going to prom without a date is boring. Demetri tries to cheer him up and explains that their classmate's party was canceled due to the library fight. Yasmine reunites with Demetri and the two dance with Moon while Eli watches the three. Sam and Miguel grab punch where they see Robby and Tory.
Louie tells Daniel and Amanda that his sister Vanessa is in her second year grad school studying child psychology. Vanessa tells the two that she wants to do an assessment on Anthony by talking to Daniel and Amanda.
Johnny goes to Cobra Kai where Terry SIlver calls him. While watching through the security camera, Terry calls him about breaking in and Johnny tells him to stay away from Robby. He tells Johnny that he's going to take care of Robby and calls Shannon special. Johnny threatens to beat them up and Silver tells him to go to a familiar street: Magnolia and Lakershim.
Back at prom, Miguel and Sam dance where the two see Robby and Tory. The two dance with each other with the latter couple watching them. Distracted, Miguel watches Tory where Sam calls him.
Vanessa is doing a therapy session with Daniel and Amanda about Anthony. She makes some hard observations about the two parents and learns of their lack of involvement in Anthony's life and how he found comfort in electronics instead of with people. Amanda is not amused by this and gets more confrontational. She is stopped when Vanessa reveals that she was testing the two of them and fails the parents. Vanessa concludes that Daniel and Amanda are the problem with Anthony.
Silver and Kreese go to the original Cobra Kai dojo where Silver talks about relocating and going back to their roots. He even tells Kreese that he plans to relocate to other places, impressing him. Later, Stingray goes to the prom where he tells Bert that he plans to hold an afterparty at his place and Bert agrees. Robby and Tory slow dance where Tory talks about the Encino kids' lifestyle. However, Miguel and Sam watch the two where this time, Sam gets distracted when she watches Robby and Miguel calls her.
Johnny learns about the original Cobra Kai dojo. He arrives but is attacked by Terry Silver. However, Kreese is shocked and horrified about how Silver lured him. He tells Silver to focus on the tournament and reminds him about their rule about not fighting before the tournament.
Back at Stingray's sister's house, the West Valley High students are having an afterparty where his neighbor confronts him. Greg insults him in front of the students and as he calls the police, Stingray breaks his hand and kicks him in the face. He resumes the party with people cheering for him.
Daniel talks to Anthony about his punishment for his suspension. He tells him that they want him to grow up and be the person he is. Anthony reveals his excitement for the All-Valley tournament wishes his father luck. When Daniel leaves, he hears a notification chime on Anthony's iPad. He is angry when he finds out Anthony wasn't taking his punishment seriously and breaks his iPad. Daniel threatens Anthony that there will be a harsher punishment if he doesn't cooperate with him and his mother.
Later on at the afterparty, Sam and Miguel get in a fight with Robby and Tory. Unfortunately, they lose the fight after Robby throws Miguel, Tory and Sam in the pool. However, Stingray jumps into the pool after mistakenly thinking that pool jumping was apart of the party.
Miguel comes home where he sees a drunken Johnny. He helps him to his bed and reveals that he loves him but he mentions Robby, saddening him.
After the party, Robby and Tory are at a carnival where they talk about the prom. Robby explains that he has to return his car and Tory also needs to return the dress. The two cap off the night by making out with each other.
Daniel and Amanda see Anthony taking out the trash where Anthony admits his mistakes to Kenny. To make amends, he offers Daniel to help him at the dealership or the dojo and Daniel agrees. Amanda praises the situation much to Daniel's reluctance.
At Cobra Kai, Terry is drinking where Stingray approaches him. He asks him if he wants to join the dojo but refuses. Despite being drunk, Terry beats him up.
- Ralph Macchio as Daniel LaRusso
- William Zabka as Johnny Lawrence
- Courtney Henggeler as Amanda LaRusso
- Xolo Maridueña as Miguel Diaz
- Tanner Buchanan as Robby Keene
- Mary Mouser as Samantha LaRusso
- Jacob Bertrand as Eli "Hawk" Moskowitz
- Gianni Decenzo as Demetri Alexopoulos
- Peyton List as Tory Nichols
- Vanessa Rubio as Carmen Diaz
- Thomas Ian Griffith as Terry Silver
- Martin Kove as John Kreese
- Paul Walter Hauser as Stingray
- Owen Morgan as Bert
- Annalisa Cochrane as Yasmine
- Hannah Kepple as Moon
- Joe Seo as Kyler Park
- Diora Baird as Shannon Keene
- Julia Macchio as Vanessa LaRusso
- Bret Ernst as Louie LaRusso Jr.
- This episode's title might be a reference to a quote in The Karate Kid Part III, when Silver and Kreese try to fight Miyagi at the dojo. They simultaneously say the phrase, "Party Time", before their fight.
- The original Cobra Kai dojo from the 1980s films is seen for the first time. Terry lures Johnny to the dojo where he attacks the former student to prove his loyalty to Kreese.
- This is Stingray's first appearance since his arrest in Season 3.