Fushigi no Umi no Nadia

Paris, 1889. Jean, a young inventor, attends the World Exposition to take part in its flying contest. But when he chances upon Nadia on the bank of the Seine, he is smitten. Jean tries to engage her in conversation, when suddenly the two are chased by a trio who is after Nadia's jewel, the Blue Water.

Having successfully fled from the three villains, Nadia spends the night at Jean's place in Le Havre. But the three return to attack the next morning in the Gratan, their multi-purpose tank. Nadia and Jean jump onto an aircraft Jean created, the Etoile de la Seine VIII, and fly off.

Jean and Nadia make a narrow escape from the trio, but their aircraft breaks down and a battleship rescues the pair. The Gratan still makes the move to attack, but they are no match for a battleship. The relief is short-lived, however, as a mysterious giant sea creature appears.

During battle with the mysterious giant sea creature, Jean and Nadia are thrown overboard. Just then, another giant sea creature appears before them…or is it?

Jean and Nadia bid farewell to the Nautilus, and head for France. But they are suddenly shot down, and crash on an island which turns out to be ruled by mysterious invaders.

After their friend Marie is abducted by invaders, Jean and Nadia infiltrate a secret base in the center of the island to try and rescue her. They discover the base was built by an organization who call themselves Neo Atlantis.