Angel no Oka
The story rotates around the mysterious place called the "Angel Island", which is somewhere in the ocean seas. Live on the island of angels some mermaids that can live on the sea, and on land. They have a human form, but can breathe both in water and on Earth. The Moon-Princess of this type of mermaid, which lives on the angel island, but is expelled for violating some of her rules. As a punishment, they put it in the sea shell and leave her drift around the sea. Meanwhile, Eyji Kusajara, the son of a rich Japanese family, meets Salge (senior sister of the moon) and tries to reveal the secrets of the angel island.