In order to keep ocean peace, PKN was organized. It consisted of the state-of-the-art battle ships of various countries. However, they were raided during the foundation ceremony by the unidentified organization, USR, which plotted to conquer the world. They couldn’t be much for the submarine UX which was operated by Admiral Red of USR. But an old Japanese submarine, the 707 saved them, which was operated Captain Haya...