Muramasa (村正, born before 1501), commonly known as Sengo Muramasa (千子村正), was a famous swordsmith who founded the Muramasa school and lived during the Muromachi period (14th to 16th centuries) in Kuwana, Ise Province, Japan (current Kuwana, Mie).[1]
In spite of their original reputation as fine blades favored by the shōgun Tokugawa Ieyasu and his vassals, the katana swords made by Muramasa gradually became a symbol of the anti-Tokugawa movement. Furthermore, in lore and popular culture from the 18th century, the swords have been regarded as yōtō (妖刀, "wicked katana").