The roots of the disaster reach back to 1600 and the Battle of Sekigahara. The Shimazu clan had opposed Tokugawa Ieyasu, and though they kept their domain in what is now Kagoshima Prefecture, they were never forgiven. Classified as a tozama, or 'outside lord,' Satsuma was always viewed with suspicion. The shogunate had a favorite tool for weakening such rivals: mandatory public works projects at the domain's own expense. By 1754, Satsuma was already drowning in debt exceeding 660,000 ryo in gold. When Shogun Tokugawa Ieshige ordered the domain to engineer a massive river separation project on the Nobi Plain, the command arrived like a death sentence wrapped in bureaucracy. Some Satsuma samurai wanted to fight rather than comply. They were overruled. The domain's chief retainer, Hirata Yukie, accepted the order on January 21, 1754, borrowed 70,000 ryo from Osaka bankers using sugar cane from Amami-Oshima as collateral, and marched 947 men northward into the floodplain.

Work began on February 27, 1754, with the Satsuma men laboring to construct dikes along the three rivers. But the shogunate's harassment was relentless and deliberate. Three times, as dikes neared completion, authorities ordered them torn down and rebuilt. Two leading samurai, Nagayoshi Sobe and Otokawa Sadabuchi, committed seppuku in protest, their deaths a pointed accusation the shogunate chose to ignore. Hirata Yukie concealed these suicides to protect the Shimazu clan from appearing weak, which could have provided an excuse for the outright confiscation of their domain. Funds evaporated under the weight of repeated demolition and reconstruction. Food was cut to a single meal and one bowl of soup per day regardless of the backbreaking conditions. Neighboring villagers were forbidden from selling straw raincoats and sandals at low prices to the workers, a petty cruelty designed to squeeze every last coin from Satsuma. Costs ballooned to roughly 400,000 ryo, equivalent to over 30 billion yen. An additional loan of 220,298 ryo was obtained from Osaka. In August 1754, dysentery swept through the camp, infecting 157 men and killing 33.

The project was abandoned on May 22, 1755. In total, 51 Satsuma samurai had committed seppuku and 33 had died of disease. Hirata Yukie, who had shouldered the impossible burden from the start, took his own life the following morning, unable to bear the financial ruin and human cost he had overseen. His death was the final act of a tragedy that had lasted sixteen months. The bitter irony was that the river works, incomplete and poorly conceived, actually worsened flooding in the years that followed. The three rivers would not be properly separated until the Meiji period, when the Japanese government brought in Dutch civil engineer Johannis de Rijke. Working from 1889, de Rijke redesigned the entire lower delta, strengthening dikes, dredging riverbeds, and constructing lock gates. The project was finalized around 1912, and his engineering gave the Kiso, Nagara, and Ibi rivers the courses they follow today.

When the rivers were finally divided successfully in 1900, a monument called the Horeki Chisuishi was erected near the river mouths, and the Aburajima Embankment was planted with 1,000 pine trees brought from Kyushu, a living connection between the Nobi Plain and the distant homeland of the men who died there. In 1938, the Chisui Jinja, a Shinto shrine, was built on the site to memorialize the 85 Satsuma samurai who perished. The embankment was designated a National Historic Site of Japan in 1940. In the city of Kaizu, kaikozu trees native to Kagoshima Prefecture line the Nanno-Sekigahara Route, now renamed Satsuma Kaikouzu Street. In Kagoshima itself, a monument and a statue of Hirata Yukie stand in remembrance. The incident also inspired Satsuma Gishiden, a gekiga manga drawn and written by Hiroshi Hirata between 1977 and 1982, whose pages capture the desperation and stoicism of men caught between obedience and annihilation.