Grey, a pirate who sails the oceans, is known as the Prince of the Ocean because he has mermaid bloodline.One day there was a battle with other pirates and they were badly defeated. Grey's ship was destroyed, the entire crew died while Grey was unconscious on the boat floating on the sea for several days. And one day a foreign ship was led by a young girl named Viona. Viona's crew saw Grey drifting in the ocean and Viona ordered her crew to take Grey.