Munechika's name comes from his maker, Sanjo Munechika, who lived in the mid-Heian period (794-1185). Munechika was an expert craftman active when Japanese sword-making technique was first established.
He is reputed to have lived on Sanjo Avenue in Kyoto during the Eien-era and thus he was known as Sanjo Munechika. He used two signatures, signing his work either Sanjo or Munechika. This blade is representative of those with the Sanjo signature and was regarded as one of the five famous swords of Japan (天下五剣, tenga goken) during the Muromachi period (1392-1573).
Initially the favourite Tachi of the Kengo Shogun, Ashikaga Yoshiteru, who is said to have fought his last battle with it, Mikazuki was claimed on his dead body by the Miyoshi family. He was once owned by Nene (Kodai-in) (1549-1624), the wife of warlord Toyotomi Hideyoshi.
Mikazuki was finally given to Tokugawa Hidetada after Nene’s death (1624), and stayed with the Tokugawa shogun family until modern times. He now resides at the Tokyo National Museum.
He is known for his unique crescent moon-shaped "Uchinoke" pattern, which represents Munechika's skilled craftsmanship. Uchinoke is a blade pattern created from its material's differences in hardness. Because of this Uchinoke pattern, this katana is known to be the most beautiful of the five famous swords.
Mikazuki’s calmness and nonchalant attitude towards life might be due to his long history of existence and narrow brush with the death that fell upon his master and fellow swords.