The Legend of the Cursed Sword Muramasa — The Ise-Kuwana Blade Said to Have Haunted Four Generations of the Tokugawa

Muramasa is a lineage of swordsmiths based in Kuwana in Ise Province (now Kuwana, Mie Prefecture), and also the collective name for the swords they made. They were active over several generations from the late Muromachi period. They were a real group of swordsmiths whose blades, known for their sharpness, were valued by Sengoku warlords as wazamono (practical fighting swords). Yet throughout the Edo period a singular legend took shape that these were “yōtō” (cursed swords) bringing ruin on the Tokugawa house, and it became one of the most famous tales of the uncanny in the history of Japanese swords.

The Real Picture of the Muramasa Lineage

The first generation of Muramasa is placed in the late Muromachi period (the Bunki and Eishō eras, roughly the late 15th to early 16th century), and the lineage continued making swords in Kuwana for several generations after that. Because it lies geographically close to Mikawa Province, the home base of the Tokugawa house, and because its swords were widely circulated in the Tōkai region at the time, this is thought to have formed the soil from which the later legend grew. Muramasa works are noted for their powerful hamon with bold irregularity, and their character, which prized cutting performance in practical use, was already highly regarded as weaponry at the time. Tokugawa Ieyasu himself possessed an uchigatana and a wakizashi by Muramasa, and it is confirmed in historical sources that these were passed down to the Owari Tokugawa house as bequests. This shows that Ieyasu did not categorically shun Muramasa swords as such.

The Muramasa lineage is said to have continued from the first generation through at least the second and third generations, and its style changed with each generation. The works of the first generation are described as having a powerful hamon based on notare with gunome mixed in, and the jigane is said to be mostly itame with masame mixed in. Their character as practical fighting swords, with emphasis on cutting performance, is strong, and the fact that warlords of the Tōkai region chose them as working swords for battle was grounded in this technical backing. Kuwana faces Ise Bay and was a key point for water transport. Its location, advantageous for procuring raw materials and distributing finished products, is also pointed out as a background to the lineage's ability to supply swords widely.

Among the swordsmiths of Ise Province, Muramasa of the late Muromachi period is the first to appear by name in the history of swords, and he established a unique position as the founder of the Sengo school based in Kuwana. The fact that water transport across Ise Bay made it easy to supply swords to Mikawa, Owari, and Suruga along the Tōkaidō is understood as the practical reason why Muramasa works reached warriors across a wide area.

Accumulated Stories of Curses

The reason Muramasa is regarded as a “yōtō” rests on the following group of anecdotes, which say that misfortune befell the Tokugawa house one after another.

First, it is said that Matsudaira Kiyoyasu, grandfather of Tokugawa Ieyasu and lord of Okazaki Castle in Mikawa Province, was cut down in Tenbun 4 (1535) by his retainer Abe Masatoyo in an incident known as the Moriyama Kuzure, and that the blade used was a Muramasa. Second, it is said that Ieyasu's father, Matsudaira Hirotada, was attacked with a wakizashi by his retainer Iwamatsu Hachiya and wounded. The year of the attack differs by source, from Tenbun 14 (1545) to around Tenbun 19 (1550), and this wakizashi was also said to be a Muramasa. Third, there is a tale that during Ieyasu's boyhood, when he lived as a hostage under the Imagawa in Suruga Province, he injured his fingers with a Muramasa kogatana. Fourth, in Tenshō 7 (1579), when Ieyasu's eldest son, Matsudaira Nobuyasu, was ordered by Oda Nobunaga to commit seppuku on suspicion of colluding with the Takeda, a theory spread that the sword used by the kaishakunin (second) was a Muramasa.

Through the accumulation of these tales of bloodshed across the four generations of Kiyoyasu, Hirotada, Ieyasu, and Nobuyasu, from the mid-Edo period onward Muramasa became the subject of kōdan and yomihon and came to be widely known among the general public as a “yōtō” that cursed the Tokugawa house.

Doubts About the Historicity of the Legend

In modern research on the history of swords, many of these tales are considered highly likely to be later accretions or embellishments. The first reason is that records remain showing that Ieyasu himself possessed an uchigatana and a wakizashi by Muramasa (the Sunpu Owakemono Odōguchō, the inventory of Ieyasu's bequest), which makes it hard to think that he thoroughly shunned Muramasa throughout his life. Second, the only relatively reliable source, Ōkubo Tadataka's Mikawa Monogatari, covers only the one incident in which Kiyoyasu was cut down with a Muramasa. The other tales rely on works of unknown authorship, forgeries, or later compilations. Third, the large circulation of Muramasa swords in the Tōkai region itself raises the probability that incidents involving Muramasa coincidentally overlapped. It has been suggested that this is the result of a simple geographic concentration rather than a causal relationship of “tatari” (curse).

On the other hand, it is said that Kampaku Toyotomi Hidetsugu also favored Muramasa before the legend spread (the “Ichi-no-dō Shichido”). As the legend grew, figures such as Sanada Nobushige (Yukimura), who fought against Ieyasu in the Osaka Campaign, were also named as Muramasa owners without basis. In the late Edo period, Saigō Takamori and other shishi of the anti-shogunate faction favored Muramasa, so that Muramasa also became a symbol of the side opposing the Tokugawa. No record has been confirmed that the Edo bakufu officially banned the possession of Muramasa swords, so there was no formal bakufu order shunning them.

Extant Muramasa Works and Their Evaluation

Today, a certain number of swords considered to be works of Muramasa survive in museums and private collections in Japan and abroad, so they are by no means rare phantom swords. On the other hand, because the image of a “yōtō” took firm hold, from the mid-Edo period some warrior households refused to keep them. As a result, many works remain whose signatures were erased, or from which the character “mura” was removed and which were changed to names such as Masamune. From the standpoint of sword appraisal, Muramasa's style has features that can be distinguished from other swordsmiths of the same era, and its evaluation as wazamono (practical fighting swords) is established independently of the narrative aspect of the “yōtō.”

Later Influence and Cultural Significance

The Muramasa curse legend was repeatedly embellished by yomihon writers and kōdan storytellers in the late Edo period. Since the Meiji period it has frequently been taken up in kabuki, novels, films, and manga as the theme of a fated sword that curses the Tokugawa. Even in contemporary popular culture, Muramasa often appears as a byword for “yōtō” and “cursed swords,” and this image, in which fact and fiction are intermingled, continues to exert a large influence on works that feature Japanese swords.

On the other hand, as swords in their own right, Muramasa works are still properly appreciated by sword enthusiasts and researchers as wazamono that received high praise for their powerful style focused on practical use. The narrative aspect of the “yōtō” and the technical evaluation of Muramasa as a practical sword are, in principle, separate matters. The Muramasa legend can be said to be a fine example showing how Japanese swords have functioned, beyond mere weapons, as symbols of political legitimacy, tales of the uncanny, and popular culture. As a narrative device of terror tied to the bloodline of the Tokugawa, the ruler of the realm (tenka-bito), Muramasa has remained a singular point in the cultural history of Japanese swords from the Edo period to the present.

Comparison with Other Famous Sword Legends

Uncanny tales about Japanese swords are not limited to Muramasa. Legends that works by a particular swordsmith are “ominous” or “cursed” are scattered across various regions. Cases like Muramasa, however, which are linked to the bloodline of a particular ruler of the realm and told as the protagonist of a four-generation chain of tragedies, are rare. In this respect, the Muramasa legend stands out as a politically charged story that goes beyond an isolated tale of the uncanny about a particular sword, and is bound up with the legitimacy and sense of fate of the Tokugawa shogunal house as a national authority. In the status-based society of the Edo period, swords were the soul of the warrior and a symbol of household standing. That is precisely why, when a narrative of “tatari” was attached to that symbol, it could carry a meaning beyond mere superstition, capable of shaking the very legitimacy of power. The reason the Muramasa legend spread among ordinary people through kōdan and yomihon is thought to lie in the universal appeal of a story of fate from which even the ruler of the realm could not escape.