In a world of magic, legends, pirates, and mythical beings, Fiore is a kingdom long forgotten. Within the deep blue of its ocean, the Obsidian, lies a lone mermaid by the name of Lucy Heartfilia. She has run from home, a home overrun by her corrupt father, and now roams the seas with her best friend Plue, a shapeshifter in the form of a white dolphin. One day, she dares the forbidden, and climbs to land. There, she possesses the legs of a mortal, and can roam as something she is fated to never be. However, when Trackers kidnap Lucy and try to sell her for her magical abilities, she manages an escape and is now on the run from the Trackers, being put under a spell that no longer allows her tail to reappear until nightfall. Stuck in a foreign place with Landwalkers, she must return home to have the curse lifted by her father, but she needs help to do it. However, she didn’t expect a pink-haired sea captain to be it. Natsu Dragneel is the captain of his beautiful Fairy Tail, but he searches for something most valuable: the pink Obsidian stone, a rare and valuable treasure that could pay millions of jewels. But the pink-haired adventurer isn’t in it for the money; no, that is a simple bonus. Natsu is in it for its wishful properties, able to grant a one and only wish to whoever takes it from the bearer. The only problem: he has no idea what it looks like, or where to find it. All he knows is that he needs it desperately. But, a beautiful maiden with the wish to return to her home in the middle of the Obsidian Sea, with Trackers after her thirsty for blood...that might be a good place to start. With an adventure full of sirens, fairies, cats and mages, the Captain and his Mermaid may just be caught by their enemies...while falling in love in the process.