Vera loves nature and adventure. That is why she is given a fish named Lemon as a pet. Now she can decorate the tank and watch Lemon swim! But one day, something strange happens: Vera falls inside the tank, which has become a whole ocean! Once in the water, Lemon will guide her through the sea, showing her life underwater... and even confronting some bad sailors who are polluting the ocean! Are you ready to join them in this surprising adventure?