When the Mishhuvurthyar menace once again threatened the Yamataian Empire at its fringes, Captain Taiyou Hoshi and Princess Ketsurui Aiko were called upon to raise a crew and re-establish their hero ship within the theater of war. Once the sole frontline starship in the Kuvexian War, the YSS Kaiyō II and its crew continue to fulfill their duty by protecting the Yamataian people while performing clandestine operations deep in enemy territory. They work to stave off the Mishhuvurthyar before they can once again imperil the Empire by whatever means necessary!