Shoan Era

The Shoan era (1299–1302) represents a pivotal period in Japanese sword history. During this time, the Bizen Osafune region in Bizen Province rapidly developed into the primary center for sword manufacturing. Military leaders commissioned large quantities of high-quality swords for themselves and as temple offerings, accelerating the development of the Bizen Osafune school and the Sōshū school. An important historical manuscript about swordsmiths compiled during the Shoan era survives to the present day, documenting famous smiths such as Nagamitsu. The era served as a crucial bridge in the evolution of sword-forging techniques from the Kamakura period kotō tradition to the Nanbokuchō period.