Kozue Amano

En 2301, la jeune Akari se rend sur Aqua, l'ancienne planète Mars, où les colons humains ont recréé le milieu terrestre, notamment en faisant fondre les glaces des pôles et recouvrant ainsi d'eau la planète à 90%. Elle s'installe à Neo-Venezia, ville inspirée de Venise dans le but de devenir une ondine, guide-touristique de la ville, et intègre la compagnie Aria tenue par un chat martien.

On the planet Aqua, a world once known as Mars, Akari Mizunashi has just made her home in the town of Neo-Venezia, a futuristic imitation of the ancient city of Venice. The technology of "Man Home" (formerly Earth) has not entirely reached this planet, and Akari is alone, having no contact with family or friends. Nonetheless, the town, with its charming labyrinths of rivers and canals, becomes Akari's new infatuation, along with the dream of becoming a full-fledged gondolier. Reverting to a more "primitive" lifestyle and pursuing a new trade, Akari becomes both adventurous and independent all at once.