????, Wada Tsumi
Kotoyoshi, Yumisuke (Story & Art)
Right(→) to Left(←)
Manga Description

In an postapocalyptic world practically covered with water, Wadatsumi, a boy who lives in that he think to be the last earth piece, knows a mysterious girl dragged by the waves of the sea. Where she comes from? There are more zones of earth in the world?! (Source: mangaupdates)