Esprit

Esprit (エスプリト) is a manga series by Taishi Tsutsui. It was serialized in Comic Blade.

Plot
"You can do anything if you put your mind to it." That is how Mio was raised... if you could call it that... by her rather lazy guardian Reki. Born on an island she has never been off of, Mio grows bored of her everyday life... That is until Sara comes along.

Sara is a member of an organization that explores and manages many "Homes", islands much like Mio's. For Mio this is her ticket to adventure, excitement and the most interesting thing of all... school! But is the school ready for Mio?