Story
After 150 years of Terraforming, Aqua, the formerly planet known as Mars, now has more than 90 percent of its surface covered in water. A young girl named Akari Mizunashi arrives at the city of Neo-Venezia, an exact replica of the old Italian city of Venice, hoping to become an Undine, the most coveted job on Aqua. (Source: TOKYOPOP) Note: Includes one extra chapter.
Synopsis via AniList (English).
Preview
From the anime adaptation: ARIA The ANIMATION.