The last Japanese soldiers stepped off Korean soil carrying nothing worth the cost.

Six years. Two invasion phases. Somewhere between half a million and a million dead across a peninsula that Japan had entered in triumph and abandoned in silence — with no territorial gain, no tribute, no acknowledgment of the sacrifices made by the hundreds of thousands of men who had served there.

The army that crossed the 朝鮮海峡 (Chōsen Kaikyō) in the spring of 1592 was the most formidable force in Asia. A full century of 戦国時代 (Sengoku Jidai) — the Age of Warring States — had produced something the continent had not seen before: an enormous military machine armed with more arquebuses than any comparable army in the world, seasoned by decades of relentless internal war, and hungry for the expansion that 豊臣秀吉 (Toyotomi Hideyoshi) had promised them. 漢城 (Hanseong) — Seoul — fell in eighteen days. Japanese forces reached Pyongyang within two months. The stated objective — march through Korea to conquer China — seemed, briefly, plausible.

Then Admiral 李舜臣 (Yi Sun-sin) began systematically destroying their supply lines.

Yi's naval innovations — including the 龜船 (kobukson, turtle ship), an iron-plated vessel designed to ram and survive — and his tactical genius in formations like the 鶴翼陣 (hakuikjin, crane-wing formation) allowed the Joseon fleet to engage and defeat numerically superior Japanese fleets along the western and southern coastlines. Without resupply, the land advance that had seemed unstoppable simply starved. Meanwhile, Ming China dispatched roughly 60,000 reinforcements in the first phase of the war. Korean 義兵 (uibyeong, righteous army) volunteer forces — farmers, Buddhist monks, former officials — harassed Japanese garrison troops continuously, making every occupied town a small siege.

The war dragged on for six years in two phases, with a brief and ultimately hollow diplomatic interval between them. Disease ravaged the occupying forces. A second invasion in 1597 reconquered much of the south but never recovered the momentum of 1592. The campaign became a drain on Japanese manpower and morale with no end in sight and no meaningful objective left to achieve.

豊臣秀吉 (Toyotomi Hideyoshi) died on September 18, 1598. The Council of Five Elders — including 徳川家康 (Tokugawa Ieyasu) — ordered full and immediate withdrawal from Korea. There was no dignified way to frame it. The war's purpose had died with the man who had invented it.

李舜臣 (Yi Sun-sin) would not let the Japanese leave quietly. On December 16, 1598, his combined Joseon-Ming fleet of approximately 200 ships caught the Japanese evacuation fleet of some 500 vessels — commanded by 島津義弘 (Shimazu Yoshihiro) — in the narrow waters of 露梁海峡 (Noryang Kaikyō). The night ambush was devastating. Japanese losses reached approximately 8,500 to 10,000 killed or wounded, with 200 to 300 ships destroyed or captured.

During the battle, an arquebus ball struck 李舜臣 (Yi Sun-sin) near his left armpit. The wound was fatal. His last command, per the historical accounts: do not announce my death. Wear my armor. Beat my war drums. He died winning the final battle of the war he had made possible.

What the war left behind defies easy summary. At least 330,000 noses — severed from Korean combatants and civilians as proof of kills for reward accounting — had been salted, pickled, and shipped to Japan during the conflict. 豊臣秀吉 (Toyotomi Hideyoshi) had them paraded through Kyoto in 1597, then interred in what became the 耳塚 (Mimizuka, Ear Mound) near the Daibutsu temple in Kyoto. The mound still exists. It is a small grassy hill in a quiet part of the city, and it contains the noses of tens of thousands of people.

Korean potters and craftsmen — abducted and brought to Japan against their will — became an unintended cultural legacy. A Korean potter taken to Kyushu discovered kaolin deposits at Arita and founded what became the 有田焼 (Arita-yaki, Arita porcelain) tradition. Japan's tea ceremony culture was transformed by the Korean aesthetics these displaced craftsmen carried with them. The war Japan fought to take Korea's territory ended up taking Korea's artisans instead — and those artisans reshaped Japanese artistic culture for centuries.

The soldiers who came home in late December 1598 arrived in a Japan already in motion toward its next catastrophe. 豊臣秀吉 (Toyotomi Hideyoshi) was dead. 徳川家康 (Tokugawa Ieyasu) and 石田三成 (Ishida Mitsunari) were moving their pieces into position. The veteran commanders of the Korean campaign — 福島正則 (Fukushima Masanori), 加藤清正 (Katō Kiyomasa), 黒田長政 (Kuroda Nagamasa) — would become the experienced core of the armies that clashed at Sekigahara less than two years later.

They came home from a war that gained nothing, to fight a war that would decide everything.