Fushigi no Umi no Nadia is set in the world of the anime Nadia: The Secret of Blue Water , where the player takes on the role of Nadia, a young girl with special abilities. She must navigate through different environments and fight against enemies to uncover the secrets of the mysterious ocean.
The gameplay involves employing one character per turn, allowing for strategic movement, skill usage, and close combat in RPG-like rounds. The characters gain experience points by defeating enemies, which helps them level up and become stronger for future sessions.