One morning, Akari wakes up to find the entire city flooded with water! It's the Acqua Alta, a once-a-year phenomenon where the water levels rise, causing all of Neo-Venezia to shut down for a day. But while most people spend the day relaxing, Aika's mentor Akira is as strict as ever, and yells at her to get back to training. Aika has just the solution to get her mentor off her back: she's running away to the Aria Company!