Mike applied as a foreign exchange student, and on a lark asked to be sent to a tropical island (which has the strange capability to sink and pop up "like a cork" a few moments later every "few hundred years or so"). She found herself dumped on a forgotten, barely mapped island populated by descendants of a British shipwreck (which is why Lu and Og, and their parents, speak perfect English). This island may be based on the real-life Pitcairn Island. The Castaways have "gone native" and are trying to behave like Polynesians, with varying degrees of success. Amongst other things, this explains Og's name and his (un)dress sense.