Munechika, the maker of this tachi blade, lived in the mid-Heian period (794-1185) and is famous as an expert craftsman active when Japanese sword-making techniques were first being established. He is reputed to have lived on Sanjô Avenue in Kyoto during the Eien era (987-989), and is thus known as Sanjô Munechika. He used two signatures, signing his works either Sanjô or Munechika.
This blade is representative of those with the Sanjô signature and was regarded as one of the "Five Famous Swords of Japan" (J. tenka goken) during the Muromachi period (1392-1573). Its distinctive form bespeaks the old style of Japanese sword making: a strong curvature from the tang through the lower half of the blade (J. koshi), but almost no curvature in the upper half (J. saki). The crescent-moon-shaped pattern (J. mikazuki) of the tempering gives the work its name, "Crescent-Moon Munechika" (J. Mikazuki Munechika).
This tachi blade was once owned by Kôdai-in (1549-1624), the wife of warlord Toyotomi Hideyoshi (1536?-1598), who later bequeathed it to the second Tokugawa shogun, Tokugawa Hidetada (1579-1632). Thus, it was passed down through the Tokugawa family.