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

Muramasa refers both to a school of swordsmiths based in Ise-Kuwana (present-day Kuwana City, Mie Prefecture) and to the blades they produced. Active across several generations from the late Muromachi period, the Muramasa smiths were real craftsmen renowned for producing exceptionally sharp "wazamono"-grade blades favored by Sengoku-period warriors. Yet over the course of the Edo period, an extraordinary legend took shape around these swords: that they were "cursed blades" fated to bring misfortune upon the Tokugawa house, making Muramasa one of the most famous eerie legends in the history of the Japanese sword.

**The Historical Reality of the Muramasa School**

The first-generation Muramasa is believed to have been active in the late Muromachi period (around the Bunki and Eishō eras, late 15th to early 16th century), with the school continuing production in Ise-Kuwana across subsequent generations. Geographically close to Mikawa Province—the Tokugawa base of power—Muramasa blades were widely circulated in the Tōkai region of the time, a circumstance that likely provided fertile ground for the later legend. Muramasa's characteristic bold, undulating hamon (blade pattern) reflected a style prioritizing combat performance, and the school's craftsmanship was highly regarded even in its own era. Historical records confirm that Ieyasu himself owned Muramasa swords and dirks in his youth, indicating he did not categorically shun the blades throughout his life.

Ise Province, alongside Mino Province, produced numerous swordsmiths from the Muromachi through the Sengoku periods, and Muramasa established a distinct identity within this milieu as a school based in Kuwana. Its access to Ise Bay shipping routes made it well positioned to supply blades to warriors along the Tōkaidō corridor toward Mikawa, Owari, and Suruga—a practical, logistical explanation for how Muramasa blades came to reach so many warriors across such a wide area.

**The Accumulation of Curse Legends**

The origin of Muramasa's reputation as a "cursed sword" rests on a cluster of incidents said to have befallen the Tokugawa house in succession. First, Ieyasu's grandfather, Matsudaira Kiyoyasu, lord of Okazaki Castle in Mikawa, was cut down by his retainer Abe Masatoyo in the 1535 incident known as the Moriyama Kuzure, reportedly with a Muramasa blade. Second, Ieyasu's father, Matsudaira Hirotada, was wounded around 1549 by his retainer Iwamatsu Hachiya wielding a Muramasa dirk, a wound from which he is said to have eventually died. Third, as a boy hostage under the Imagawa clan in Suruga Province, young Ieyasu reportedly cut his hand on a Muramasa knife. Fourth, when Ieyasu's eldest son Matsudaira Nobuyasu was ordered by Oda Nobunaga to commit seppuku in 1579 on suspicion of collusion with the Takeda clan, legend holds that the executioner's blade was a Muramasa.

The accumulation of these bloody episodes across four generations—Kiyoyasu, Hirotada, Ieyasu, and Nobuyasu—fueled the spread of the "cursed Muramasa" narrative through kōdan storytelling and popular fiction from the mid-Edo period onward, embedding it deeply in popular consciousness.

**Doubts About the Legend's Historicity**

Modern sword-historical scholarship largely regards much of this narrative as later embellishment. First, records confirming Ieyasu's own ownership and use of Muramasa blades make it implausible that he shunned them absolutely throughout his life. Second, contemporary sources verifying that the blades involved in Kiyoyasu's and Hirotada's deaths were genuinely Muramasa are scarce; most accounts rely on later compiled chronicles and war tales. Third, the sheer prevalence of Muramasa blades in the Tōkai region raises the possibility that their statistical involvement in various incidents was coincidental rather than a matter of curse or causation—a simple consequence of geographic concentration rather than supernatural fate.

At the same time, a separate anecdote holds that Toyotomi Hidetsugu favored Muramasa blades, and that the Toyotomi side sought them out during the Osaka Campaign as a form of symbolic curse against the Tokugawa—suggesting that rival powers may have deliberately exploited the "cursed sword" image against Ieyasu's house for political and psychological effect. No official Tokugawa shogunate edict banning possession of Muramasa blades has been confirmed to exist.

**Later Influence and Cultural Significance**

The Muramasa curse legend was repeatedly elaborated by Edo-period yomihon writers and kōdan performers, and from the Meiji era onward it became a recurring motif in kabuki, fiction, film, and manga as "the fated blade that curses the Tokugawa." In contemporary popular culture, Muramasa frequently appears as a byword for "cursed sword," and this blend of fact and fiction continues to shape creative works involving Japanese swords.

At the same time, Muramasa blades themselves continue to be legitimately valued by sword enthusiasts and researchers as combat-oriented wazamono of genuine technical merit—an assessment entirely separate from the "cursed" narrative. The legend of Muramasa stands as a compelling example of how a Japanese sword could transcend its function as a weapon to become a symbol of political legitimacy, eerie legend, and popular culture, and it remains a singular point in the history of Japanese sword culture, functioning as a narrative device for fear surrounding the bloodline of the Tokugawa house from the Edo period to the present day.