One day in the spring of 1701, Asano Naganori, a minor daimyo charged with making the arrangements for the reception of the imperial emissary, suddenly rushed at Kira Yoshinaka, the shogunal advisor on etiquette, in Edo Castle and swung at him with a short sword — injuring but not killing him — before being restrained.

Forty-Seven Samurai: A Tale of Vengeance and Death in Haiku and Letters, by Hiroaki Sato.

264 pages

STONE BRIDGE PRESS, Nonfiction.

By nightfall Asano had been ordered to commit seppuku for his breach of etiquette, setting in train a course of events that would engulf hundreds of lives, leaving scores dead and wounded, and creating one of the greatest sagas of Japanese feudal loyalty and revenge.

The bare historical facts of the 47 samurai saga are incredible and thrilling. Knowing that shogunate reprisal for Asano’s rashness would be visited on the whole clan, within hours of his arrest his entourage were hot-footing it back to their domain in western Honshu, covering a journey that usually took 15 days in just five.

Asano’s Ako clan was soon made aware that its castle and lands were to be handed over to the shogunate and all the samurai made ronin (masterless samurai), losing their ranks and precious rice stipends on which they, and their families, depended.

Hiroaki Sato | COURTESY OF HIROAKI SATO

The bigger question was: How could they avenge the sudden downfall of their master and the entire clan? Feudal justice seemed to demand that Kira Yoshinaka be slain in vengeance, yet he was protected by the powerful Uesugi clan and his association with the shogunate.

Nearly two years would pass until, after making elaborate preparations and spying on Kira’s movements, one snowy December night, 47 of the aggrieved samurai of the Ako clan attacked the front and rear of Kira’s Edo mansion, taking by surprise the 100 people within. Sixteen of the household were killed and 21 injured in the ensuing fight before the ronin found Kira, slayed and beheaded him, and proceeded to the graveyard at Sengakuji temple where their master was buried in order to present him with Kira’s head.

Satisfied in the execution of their revenge, the samurai handed themselves over to the shogunate authorities without a fight, fully expecting to die. Debates raged as to what should happen next. Some of their captors, from the Hosokawa clan, regarded the men as a superb embodiment of the warrior loyalty code and supplied them with the finest food, hoping they would be released.

Others, connected to Kira and close to the shogunate, argued that they should be executed as common criminals. Eventually, following the advice of the Confucian scholar Ogyu Sorai, it was concluded that they should be allowed to commit seppuku — supposedly death with honor, though their grim executions took many hours as blood-soaked tatami mats had to be repeatedly changed.

Into this already extraordinary and much-written-about tale, Hiroaki Sato weaves a rich portrait of a paradoxical society governed by value systems vastly different to our own. Private killings were rife and sanctioned by the Confucian code — filial loyalty to a father or elder brother demanded that murders be avenged. The shogunate indeed encouraged registration of intentions of revenge, which on occasion might be fulfilled by embittered siblings and children only after a decades-long pursuit of enemies across the length and breadth of Japan.

At the same time, the shogunate was savage in its meting out of punishment for slight moral transgressions and threats to its authority — crucifying and hanging with impunity. Amid the constant murders and capital punishments, more widespread tragedies periodically visited: In the provinces, there were famines claiming tens of thousands of victims and a great fire in Edo in 1657 that left 100,000 dead.

Yet bizarrely, Japan in the Genroku Era (1688-1704) — when the “Ako Incident” occurred — was ruled over by the shogun Tsunayoshi who, convinced he had produced few heirs because he had killed animals in a previous life, issued edicts making it illegal to harm all sentient beings.

Known to history as the “dog shogun,” he had kennels installed in west Edo to house 144,000 dogs and demanded that owners who were negligent in their care of dogs be subject to capital punishment. Sato wryly remarks that the more likely cause of Tsunayoshi’s lack of heirs — despite a shogunal harem — was that he was far more sexually interested in his entourage of 150 page boys.

Resolutely bloodthirsty and uncompromising, many of the samurai of the age — some of the Ako ronin included — also had their poetic sides, composing haiku and tanka poems, including jisei (death poems). They were also the subject of many poetic verses, often employing humorous wordplay, which are translated and analyzed in Sato’s work.

We emerge from this erudite book having viewed the feud from multiple perspectives, but what was the original cause of the incident that unleashed such bloodletting and three centuries of romantic writing on the subject?

It seems that Kira was accustomed to receiving bribes from each daimyo successively charged with arranging the annual welcome of the imperial emissary in exchange for giving his advice on etiquette. Asano, in his duties, seems to have been a bit of a skinflint, seeking to cut back on his clan’s expenses, encouraged by the shogunate’s own promotion of thrift.

An argument over accounts was to leave an awful lot of people dead and a considerable number of Japan’s greatest modern authors — from Akutagawa Ryunosuke to Hisashi Inoue — inspired to give their take on one of Japan’s most sprawling and endlessly intriguing of bloody epics.

Now Sato makes his strike.

Hiroaki Sato wrote the “The View From New York” column for The Japan Times from 2000 to 2017, and continues to contribute on a freelance basis.