The series centers on brothers Brady (Mitchel Musso) and Boomer (Doc Shaw), a pair of 16-year-old twins raised by their aunt and uncle in Chicago who live a normal existence. However, when Mason (Geno Segers), the royal adviser to the throne of the island of Kinkow, arrives at their high school, they learn that they are the heirs to the throne of the island, and after Mason tells Brady and Boomer of their lineage, they begin to realize that their lives are about to change dramatically.
After making the discovery, the brothers relocate to Kinkow, an island to assume their roles as the joint kings of the island nation, which has many odd customs and superstitions – while trying not to cause problems. Actually, the oldest twin was supposed to rule alone but, since all records of which twin (Brady or Boomer) is the eldest were lost, the two of them must rule together. Boomer and Brady's efforts are often aided by Mason's teenage daughter Mikayla (Kelsey Chow) and hindered by Lanny (Ryan Ochoa), a disgruntled cousin who's out to sabotage the boys and take the throne for himself, because he was supposed to be heir to the throne before they found out of Brady and Boomer.
- Mitchel Musso as Brady (20/20)
- Doc Shaw as Boomer (20/20)
- Kelsey Chow as Mikayla (16/20)
- Ryan Ochoa as Lanny (20/20)
- Geno Segers as Mason (16/20)
- Eve Sigall as Old Hag (5/20)
- Vincent Pastore as the voice of Yamakoshi (4/20)
- Derek Anthony as Guard (4/20)
- Tichina Arnold as Aunt Nancy (2/20)
- John Eric Bentley as Uncle Bill (2/20)
- Gragory Pugliese as Rondo (2/20)
- Edward ˝Grapevine˝ Fordham as Wally (2/20)
- Matthew Willig as Tarantula Leader (2/20)
- Aaron Aguilera as Tarantula Warrior (2/20)
- Martin Klebba as Hibachi (2/20)
- Doug Tait as Big Pupaley (2/20) / Mummy (1/20)
- Clint Culp as P.E.Coach (1/20)
- Maxxie J.Santillan Jr. as Stately Islander (1/20)
- Chuck Hittinger as Skeg (1/20)
- Leslie Anne Huff as Aerosol (1/20)
- Madison Riley as Amazonia (1/20)
- Paul A.Costa as Roger (1/20)
- Ben Geroux as Pupaley (1/20)
- Danny Seckel as Jerry (1/20)
- Ted Rooney as Royal Tracker (1/20)
- Christoph Sanders as Tristin (1/20)
- Davis Cleveland as Chauncey (1/20)
- Leland Crooke as The Professor (1/20)
- Doug Brochu as Oogie (1/20)
- Michael Carbonaro as Royal Yes Man (1/20)
- Jack Depew as Team Captain (1/20)
- Chris Wylde as Two Peg (1/20)
- Noah Crawford as No Beard (1/20)
- Chris Blasman as Hawk (1/20)
- Logan Browning as Rebecca 'Awesome' Dawson (1/20)
- Sinqua Walls as Pierce (1/20)
- Greg Eagles as Shaman Tarantula (1/20)
- Bill Bulender as Keyboard Prisoner (1/20)
- Raymond Ochoa as Young Boy (1/20)
- Edie McClurg as June (1/20)
- Patrick Gallagher as Farhog the Fierce (1/20)
- Tiffany Mulheron as Princess Iris (1/20)
- Oliver Muirhead as King of Cornia (1/20)
- Tyrel Jackson Williams as Hilo Tutuki (1/20)
- The Great Khali as Atog the giant (1/20)
- Adoni Maropis as The Oracle (1/20)
- Jane Yamamoto as Jane the Interviwer (1/20)
|Return of the Kings||Writer: Dan Cross & David Hoge||Director: Linda Mendoza||September 10, 2010||#1x01|
|Brady and Boomer are twin teens. After being bullied by the toughest guys in the whole school, Mason and a group of warriors from their kingdom in Kinkow come to bring them home. They break the sacred ruby and the volcano on the island erupts. Lanny tricks them into going to get another sacred ruby so they would die in the dark side of Kinkow. While they were in the dark side, Brady and Boomer were caught by the Tarantula People. Luckily, Brady has the chain that controls them. They were able to get the sister ruby, and save the kingdom. However, the chain that controlled dangerous tarantula men on the dark side of the island falls off Brady's neck. The men find it and use it to awaken a mummy on the dark side.
|Beach Bully Bingo||Writer: Matt Wickline||Director: David Kendall||September 22, 2010||#1x02|
|Brady and Boomer are banned from the beach by the top surfer Hibachi. After that, they return and they make an impossible bet with Hibachi that they will beat him in a surf competition and take back the beach. Hibachi states that if he wins, then no one will be able to surf on the island ever again, but him and his friends. Brady and Boomer enlist in a boot camp run by Mason, who attempts to train them so they can learn how to surf. Brady and Boomer train and take on Hibachi, while Mikayla decides to keep an eye on Hibachi's friends. She discovers that they were trying to cheat by shining light from the sun into the eyes of Brady and Boomer by using a reflective shell. She puts the ones responsible to sleep with darts. Brady and Boomer win the competition, and make Mason the new "Big Kahula".
|A Mermaid's Tail||Writer: Donald Beck||Director: Andy Cadiff||September 24, 2010||#1x03|
|The two kings find mermaids on the beach and bring them to the castle to turn them into human princesses of the castle. Things go bad when the mermaids take over the castles and turn Mikayla into a mermaid. Meanwhile, Lanny falls in love with one of the mermaids.
|Where the Wild Kings Are||Writer: Kenny Smith||Director: Victor Gonzalez||October 8, 2010||#1x04|
|Brady and Boomer find a cute creature in the jungle and decide to keep it as a pet, despite Mason's warnings. The pet acts a bit like a Pokemon, and Lanny calls him a "Giant Armpit". It starts off well, but gets worse when they start neglecting it and turns into a large beast, kidnapping the kings in the process. Meanwhile, Lanny hypnotises the talentless court jester to finish off the kings which as all of his plans do, it fails.
|Big Kings On Campus||Writer: Dave Polsky||Director: Leonard R. Garner||October 13, 2010||#1x05|
|Brady gets jealous when Mikayla starts hanging out with her friend Tristan who is into extreme sports. To impress her, Brady joins school and tries to do extreme sports. Meanwhile, when Boomer and Brady are placed with all the little kids, Boomer becomes attached with the kids.
|The Brady Hunch||Writer: Sean Cunningham & Marc Dworkin||Director: Victor Gonzalez||October 22, 2010||#1x06|
|Boomer becomes good friends with a boy from the Flaji clan, a neighboring tribe that Brady begins to suspect are cannibals and want to have Boomer for dinner, so he hatches a plan and attempts to infiltrate the tribe's village, while Mason also gets the crazy cannibal theory in his head.
|Junga Ball||Writer: Matt Wickline||Director: Victor Gonzalez||October 29, 2010||#1x07|
|The guys get ready for the Junga Ball tournament against other islands so Brady becomes the leader of the guards who made the team. When Boomer doesn't get to rule the team as much as Brady, Boomer starts his own team with help from Kinkow's residents. The two teams compete to see which team would represent Kinkow.
|Revenge Of The Mummy||Writer: Dan Cross & David Hoge||Director: Adam Weissman||November 8, 2010||#1x08|
|The mummy gets revived with help from the bat medallion and he starts haunting the kings. The kings try to get it back before Mikayla and Mason find out.
|Oh Brother, Where Arr Thou||Writer: Sean Cunningham & Marc Dworkin||Director: Andy Cadiff||November 15, 2010||#1x09|
|A pirate gives Boomer and Brady a riddle to solve that supposedly will lead them to a magical coin but the puzzle is actually a trap to ensnare the brothers so the pirate can steal the royal treasure.
|No Kings Allowed||Writer: Matt Wickline, Dan Cross & David Hoge||Director: Joel Zwick||November 22, 2010||#1x10|
|Brady and Boomer want to join the Riptides, a gang famous for pulling pranks all over the island. Their final test before they will be accepted into the gang is stealing Yamakoshi; Lanny's pet fish.
|Pair of Jokers||Writer: Donald Beck||Director: Adam Weissman||December 3, 2010||#1x11|
|When Brady and Boomer attempt to pull pranks on the villagers, they go too far and karma comes full circle, just as Mikayla said.
|Pair of Prom Kings||Writer: Sean Cunningham & Marc Dworkin||Director: Eric Dean Seaton||December 17, 2010||#1x12|
|Brady and Boomer head back to their high school prom in Chicago to flaunt their royal status. Boomer chooses a girl named Rebecca, who he thinks he once had a date with and Brady chooses Mikayla who refuses for then till she see's something noble of the king, but till then things go haywire when the Tarantula People crash the party.
|Tone Deaf Jam||Writer: Donald Beck||Director: Linda Mendoza||December 17, 2010||#1x13|
|The kings must perform for the islanders at the Annual Harvest Festival, and Boomer can't wait to show off his singing skills, neither can the islanders since it is known for all the past kings to have amazing musical talent called 'the chiming'. Brady knows Boomer has a horrible voice, but doesn't have the heart to tell him. When Brady's plan to protect his brother from humiliation backfires, Boomer discovers Brady is a terrific singer and arranges for Brady to sing to the kingdom. Boomer tries to sing a song called 'Kaboomer' in this episode.
|The Bite Stuff||Writer: Dan Cross & David Hoge||Director: Victor Gonzalez||January 14, 2011||#1x14|
|Feeling homesick, Brady and Boomer call Aunt Nancy and Uncle Bill to check in, but accidentally end up scaring them with their tales of Tarantula people, quick sand and giant bugs. While Aunt Nancy and Uncle Bill rush to the island to bring the twins back to Chicago, Brady is accidentally stung by a dangerous Waka Waka bug. With the help of Mason and Mikayla, the kings must hide Brady's strange side effects which include bubble butt, elephant ears, angry amnesia, bug eyes, linguine limbs, and pumpkin head. Brady, Boomer, Mikayla, and Mason must prove that the island is safe enough for the kings to stay and rule.
|Brady Battles Boo- Mer||Writer: Sean Cunningham & Marc Dworkin||Director: Linda Mendoza||January 21, 2011||#1x15|
|After watching a scary movie, Brady is convinced that the castle is haunted and sets out to prove to Boomer that ghosts exist. Lanny escorts Brady to a spirit shop where he asks for the wimpiest "Ghost-in-a-Can." However, Lanny deviously switches Brady's can with the ghost of Farhod the Fierce, a ruthless Viking warrior. When unknowingly releases the dangerous ghost, Farhod possesses Boomer's body and takes over the castle. Now, Brady must conquer his fear of ghosts in order save his brother and the island kingdom.
|The King and Eyes||Writer: Sean Cunningham & Marc Dworkin||Director: Leonard R. Garner||January 31, 2011||#1x16|
|The two kings are told that they have to try to win a competition when they attempt to arrange a treaty with an adversary island; the winner receives the reward of a princess, but Brady and Boomer discover she is not a typical princess.
|The Kings Beneath My Wings||Writer: Chris Atwood||Director: Robbie Countryman||February 7, 2011||#1x17|
|The kings decide to have a king for a day contest and a boy named Hilo Tutuki wins. He thinks that the kings are super cool when they aren't but everyone gets into trouble when Hilo tries to stop a dangerous beast.
|Fight School||Writer: Eric Lev||Director: Linda Mendoza||April 18, 2011||#1x18|
|After learning their father was the best warrior in island history, Boomer and Brady enroll in Kinkow Fight School. When Mason gives the kings special treatment, jealousy overcomes Mikayla. Taking Lanny's advice, she decides to test the kings' newfound confidence and skills by pitting them against Atog the Giant. But when Mason finds out, Mikayla tries to get the kings to back down, but it's too late, the kings are eager to prove their inner warrior. Then when they fight, Atog wins by far. Then when Mikayla sees that Atog got confused when they use some American Wrestling. So then they win over Atog by mixing wrestling with Kinkow fighting.
|The Trouble With Doubles||Writer: Lisa Muse Bryant||Director: Eric Dean Seaton||April 25, 2011||#1x19|
|Boomer and Brady discover Vault 14, a secret vault which protects Kinkow's most mysterious and powerful artifacts including Duplicatus Plantus, a plant that copies anything it touches. The kings make clones of themselves and while they go surfing, they send their doubles to the Kalooki Island Peace Summit. Filling in for the brothers, the clones impress Mikayla, the island dignitaries and the other Kinkowians with their intelligence, hygiene, and professionalism. However, when Brady and Boomer overhear the clones' ultimate plan to takeover, the kings must figure out how to get rid of their doubles and take back their kingdom.
|Journey to the Center of Mt. Spew||Writer: Dan Cross & David Hoge||Director: Victor Gonzalez||May 2, 2011||#1x20|
|It's the kings' birthday and for their royal present, they each get one wish that will come true. Right before blowing out the candles, Boomer learns that Brady has been bragging to the entire island that he is the older twin. Boomer uses his wish to find out the truth about who was born first, while Brady's wish is that Mikayla compliments him all day. Boomer travels to the center of Mt. Spew to meet with the volcano's Oracle and learn who is the older king, but the younger brother will no longer be co-king if it is known who the older brother is. So Brady, Mikayla, and Mason chase after Boomer.