It's 1889 and Paris is welcoming the world to the Exposition Universelle. People from around the globe have flocked to the French capital to see the best scientific and cultural achievements, getting a glimpse of the wondrous age that awaits them in the 20th century. Though progress is rapidly changing the world, this is still a romantic age filled with adventure and the unknown. But there's also darkness. Gigantic, mysterious sea creatures roaming the world's oceans are terrifying people. They abduct the father of an invention-loving boy named Jean. He meets an enigmatic girl called Nadia at the Exposition and it's love at first sight. Jean soon finds himself embarking on an adventure with Nadia. What fate awaits them?

[Source: NHK ENTERPRISES]

Three years after the defeat of Gargoyle and Neo-Atlantis, a new threat has surfaced bent on bringing the world under his control. Geiger, using advanced robot technology, is attempting to begin a world war, and take control of the devistated world after the destruction has stopped. Once again, Nadia and Jean must fight to save the world, only this time from itself.

[Source: Anime News Network]

Short Omake "extra" episodes which were included as a bonus on the Japanese LaserDisc set.