The series centers on brothers Brady and Boomer (Mitchel Musso and Doc Shaw), a pair of 16-year-old fraternal twins raised by their aunt and uncle in Chicago and live a normal existence. However, when Mason (Geno Seger...展开s), 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 king's 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 American island part of Polynesia 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 eldest 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 Mikayla (Kelsey Chow), Mason's teenage daughter and hindered by Lanny (Ryan Ochoa), a disgruntled cousin, who's out to sabotage the boys and take the throne for himself.