PARANORMASIGHT: The Mermaid's Curse

The remote island of Kameshima sits nestled in Ise bay.
Yuza Minakuchi is a young pearl diver who lives on the island and spends his days underwater gathering, together with his best friend Azami Kumoi. After he has a bewildering supernatural experience encountering another version of himself on the ocean floor, a series of curses start to befall the island...
A girl of unknown origins, a treasure hunter from a foreign land and a mysterious housewife investigating a drowning. Paths cross and destinies collide as they come closer to the secret of the Mermaids of Ise, a legend that has been obscured by the fog of history for so long.

[From Steam]