Ten years ago, a tragic shipwreck separated Fena Houtman from her childhood friend Yukimaru and claimed her father's life. Now, at 23, she is confined to an island, destined to spend the remainder of her life selling herself to men. On the night she is to be forcibly married to a client, Fena devises a plan to escape her employers, but two old acquaintances unexpectedly intervene and assist her in fleeing. The trio rushes toward the open sea and arrives at Goblin Island—a mysterious territory that serves as the home of a clan of fierce warriors. It is here that Fena discovers her father's ill-fated final voyage was undertaken in search of a place called "Eden," the location of something vital he needed to protect. With only a clear crystal as a clue, Fena is tasked with locating this place, as she is the only one capable of doing so. While still weighing the search for what her father left behind, Fena reunites with Yukimaru, who urges her to accept the quest. Now commanding a seven-person crew, Fena must navigate the high seas in pursuit of Eden. However, as uncanny groups begin to target her, the perilous journey proves to be even more challenging than it initially appeared.