Aoi Umi no Tristia: Nanoca Flanka Hatsumei Koubouki

The island of Tristia was once an important port city for maritime trade. A veritable jewel of the ocean where merchants, sailors and travelers flocked to for its booming commerce. That was before the dragons attacked and destroyed the city. Although the citizens have worked hard to rebuild, setbacks occurred which plunged Tristia deeper into despair.
In an emergency plea for help, the people of Tristia send an urgent communiqué to the legendary inventor Prospero Flanka for his aid in reviving the fortunes of the city. The Tristians wait for Prospero anxiously but when the fateful day arrives, it is not he who appears but his 14 year-old grand daughter Nanoka, a highly skilled inventor in her own right.