Blue Inferior

Blue Inferior (ブルー・インフェリア, Burū Infiria) is a manga created by Kyoko Shitō. The manga was serialised in Kadokawa Shoten's Kibou Comics. The manga is licensed in English by ADV Manga.

Plot
Because of the environmental pollution, the Earth has become a contaminated desert, there are only patches of land. Some to be said to be inhabited by "sub-humans", contaminated people. However, there are a few areas along the shore where normal people live, but they've become suspicious of strangers, and know nothing of the people of the outside world.

One day, a young girl named Marine washes up on the shore of one of the inhabited lands. She has no memory of where she came from. She is found by a young boy named Kazuya, who loves the sea and has a natural curiosity about the outside world. The two of them become friends but then rumors start spreading that Marine might be a sub-human, and she is locked up. Now Kazuya must help her escape, and uncover the mystery of who she is and where she came from.