|Battle of Jade Sea|
|Part of the Unification of Yamato|
| Yamato Empire|
Clergy of Mardük
| Yasuo Fukuda|
| Kuro Tori|
Yousei Kaizoku (POW)
|Unification of Yamato|
The Battle of Jade Sea was a naval engagement fought between the armada of the Yamato Empire led by Admiral Yasuo Fukuda and the pirate fleet of the Blue Dragons led by Pirate King Kuro Tori near the pirate's hideout in the Jade Sea during the final stages of the Unification of Yamato. Ultimately the imperial navy was victorious and crushed the pirate fleet although Kuro Tori managed to slip away in the chaotic aftermath. Hundreds of pirates lost their lives while several prominent pirate captains such as Yousei Kaizoku were captured and would later be brainwashed to act as loyal servants of the Empire for the upcoming conflict with other nations as per Shogun Masamori Hyuga and High Cleric Distreyd Thanadar XII's plan to expand the reach of the Yamato Empire.
- See: Battle of Port Hawke
After having successfully taken over Port Hawke on Falgorn Island, the combined forces of Shogun Masamori Hyuga and High Cleric Distreyd Thanadar XII set their eyes on one of the last remaining pockets of resistance in Yamato: pirates, particularly the Blue Dragons led by the Pirate King Kuro Tori. In order for the Unification of Yamato to truly be successful, the pirates had to be dealt with.
Distreyd focused his efforts on gathering the forces of the Clergy of Mardük for the Shogun to use, and meanwhile the Shogun appointed Admiral Yasuo Fukuda to find and wipe out the pirates unless they pledged themselves to him.
Admiral Fukuda's agents scoured the Jade Sea for a long time, unable to find the hidden pirate base, but they attacked any pirate vessel they came across in several small-scale naval battles. Head Wizard Jaotu Hyuga, who was both the Shogun's brother and the Admiral's advisor for the campaign, eventually came up with another plan: to bribe a select few pirates with promises of wealth, fame and followers--as well as a pardon of their crimes--if they revealed their brethren's hideout to the imperial navy. Where brute force hadn't helped, cunning might provide better results.
Jaotu's plan turned out to be successful when he eventually managed to locate one such opportunistic pirate, Wilheim Maddingway, whom he convinced to aid him and Fukuda. Maddinway's greed got the better of him, and he betrayed his comrades and superior officer, Captain Yousei Kaizoku, by slipping to the imperial navy in the dark of the night. He revealed a safe passage into the Pirates' Cove in exchange for a large fortune and a promise to become an influential captain in the imperial navy.
Admiral Fukuda's forces began the attack at dawn, bombarding a wide area around the Cove with spells of dark magic. The Blue Dragons, realizing that they had been found, responded boldly: instead of staying in the safety of their Cove to either die of starvation, in-fighting or being blasted by the armada's spells, they instead sailed out of the Cove under the leadership of Kuro Tori to face the imperial navy in open combat with their other pirate fleets they had been negotiating with.
Admiral Fukuda hadn't expected such a bold move from the pirates, but he quickly sent out orders to his commodores to engage the pirates in combat. Although the pirate ships were smaller and faster than the bulkier Yamatian ships, the imperials had firepower on their side thanks to several mages from the Clergy of Mardük who were backing them up.
After a long and fierce battle, the Admiral's navy prevailed and sank several pirate ships, killing hundreds of pirates and capturing some noteworthy captains, one of whom was Yousei Kaizoku. The reign of the Blue Dragons on the southern Jade Sea had come to an end at last.
- See: Yamatian Invasion
Pirate King Kuro Tori was nowhere to be found after the battle despite lengthy searches for his body, and the imperials assumed he had drowned with his ship. However, he had survived and had used the chaotic aftermath of the battle to his advantage to slip away and lick his wounds.
Yousei Kaizoku and other surviving pirate captains were brought to Ryugashi, the Hyuga capital, where Jaotu Hyuga experimented on them. The Head Wizard eventually cast a geas on the pirates combined with brainwashing to make them loyal servants of the Yamato Empire--a fate worse than death for freedom-loving pirates. Yousei Kaizoku found out later who had betrayed the crew and was allowed to get his hands on the traitor Maddingway who died a slow, agonizing death.
With the pirates' defeat the Unification of Yamato was finally complete. Masamori Hyuga and Distreyd Thanadar decided to begin a new campaign to conquer neighbouring kingdoms in what would be known as the Yamatian Invasion. Yousei Kaizoku, whose skill and cunning had been recognized, was appointed as one of the Admirals of the Yamatian Navy and was sent with his former enemy, Admiral Yasuo Fukuda, to invade Libaterra, thus announcing Yamatian intentions to take over the world.