The Rise of Nihon Maru: A Floating Symbol of Power

In 1591, as Japan prepared for its ambitious invasion of Korea under the command of Toyotomi Hideyoshi, a remarkable warship emerged from the docks of its naval arsenal: the Nihon Maru (“Japan Ship”). Built by the naval commander Kuki Yoshitaka, this vessel was no ordinary warship—it was a floating fortress designed to awe enemies and embody the might of Hideyoshi’s regime.

Belonging to the atakebune class (large armored warships), the Nihon Maru stood out for its sheer size and architectural grandeur. Its three-story tenshu (castle keep) featured three 18-mat rooms, whitewashed walls, and elegantly curved roofs, resembling a traditional Japanese castle set adrift. Initially serving as a goza bune (royal yacht) for Hideyoshi, it was later thrust into combat during the Imjin War (1592–1598), where it became a symbol of Japan’s naval ambitions—and vulnerabilities.

The Imjin War and the Battle of Angolpo

The Nihon Maru’s most famous engagement occurred at the Battle of Angolpo in 1592. Following a devastating defeat at the hands of Korean admiral Yi Sun-sin’s turtle ships at the Battle of Hansando, the Japanese fleet, led by Wakizaka Yasuharu, retreated to Angolpo harbor. Yi pursued, launching a surprise attack. As the battle raged, the Nihon Maru entered the fray, its decks adorned with Shinto-inspired Mount Horai motifs and draped in brocade curtains meant to deflect arrows.

Korean chronicles describe the ship’s dramatic resistance:

> “When fire arrows rained down, we dragged the charred debris into the sea. The Koreans closed in, firing half-bows—their arrows piercing the first two layers of curtains but stopping at the third. Then, their cannons struck. A three-foot hole tore through the hull, but the carpenters, prepared for such damage, swiftly patched it.”

Despite its resilience, the Nihon Maru was outmatched by Yi’s innovative tactics. Notably, Japanese records from Angolpo mark the only known mention of Korean turtle ships in their literature, describing them as ironclad vessels armed with cannons and fire arrows.

Survival and Legacy

Miraculously, the Nihon Maru survived the war. Returned to Toba, it was refitted and renamed Tairyu Maru (“Great Dragon Ship”). It remained there until 1856, rotting away, though its intricately carved dragon figurehead endured until 1945, when it was destroyed in a U.S. bombing raid during World War II.

Japan’s Naval Innovations: Beyond the Nihon Maru

### Floating Siege Towers and Horse Transports

The Nihon Maru was just one example of Japan’s naval ingenuity. The seiro bune (siege tower ship) featured a square tower replacing its deck, allowing gunners to rain fire on coastal fortresses. Meanwhile, the uma fune (horse transport) used pulleys to hoist horses aboard—a critical innovation for campaigns like the invasion of Korea.

### The Blind Ships of Osaka

During the 1614–1615 Siege of Osaka, the mekura bune (“blind ship”) debuted. Shielded by bamboo screens and armed with European-style breech-loading folangji cannons, these vessels bombarded Osaka’s defenses with unprecedented firepower. Each cannon required a three-man crew, reflecting the growing sophistication of Japanese naval warfare.

Naval Combat: From Arrows to Gunpowder

### The Age of Boarding Tactics

Early Japanese naval battles, like the 663 Battle of Baekgang, relied on archery and boarding actions. By the Genpei War (1180–1185), ships became floating battlegrounds, with the famous Dan-no-ura clash decided by close-quarters combat.

### The Pirate Legacy

The wokou (Japanese pirates) perfected boarding tactics, prioritizing capture over destruction. Even in the 16th century, naval battles like the Battles of Kizugawaguchi followed this tradition—volleys of gunfire preceded sword duels on deck.

### The Imjin War’s Lessons

Yi Sun-sin’s victories exposed Japan’s overreliance on boarding. At the Battle of Myeongnyang (1597), Korean sailors repelled waves of Japanese boarders with spears and stones, while the disastrous Battle of Sacheon (1598) saw stranded Chinese ships overrun by Japanese troops—a rare, if chaotic, boarding success.

Conclusion: The Echoes of Nihon Maru

The Nihon Maru and its contemporaries reveal a fascinating chapter in naval history—one where aesthetics, religion, and warfare intertwined. Though Japan’s boarding-centric tactics often faltered against advanced firepower, its innovations laid groundwork for later naval doctrines. Today, the Nihon Maru endures as a symbol of ambition, adaptation, and the enduring allure of the floating castle.