You are the last citizen of Laputa, the legend of a floating castle once inhabited by humans, a paradise on earth. It's been lonely with no other humans, but you've got the friendly robots and animals by your side. Besides, carrying the royal Laputa blood, you cannot abandon your kingdom.

One day, you're simply going out in the gardens when you hear cheerful laughter and spot two people, around 12 years old, rolling in the grass.