The Pyross have red skin, and stocky, muscular features; water burns their flesh and rain is lethal to them.

The Hydross, on the other hand, have curvy features and blue or turquoise skin, and water is vital to them.

The two people know very little about one another, and they cannot even touch one another, as the contact of Hydross skin burns the Pyross, and vice versa.

The setting and synopsis of the film were freely adapted from Serge Brussolo's novel À l'image du dragon, with a slightly lighter tone.

The characters, backgrounds and general looks of the film were conceived by French illustrator and comic author Caza.