Shintō, translated as “new sword,” marks an intriguing period in Japanese swordmaking, situated between the kotō and shinshintō eras. Traditionally, shintō swords are defined as those crafted from around the Keichō era (1596-1615) to approximately the An’ei era (1772-1781), representing a dynamic phase of innovation and evolution in sword craftsmanship.

The term “shintō” originally denoted newly forged or made swords, contrasting with older blades referred to as “arami.” Over time, the meaning of shintō evolved, with its modern interpretation stemming from publications such as Arami Mei Zukushi and Shintō Bengi during the Edo period. The precise division between kotō and shintō, often attributed to the Keichō era, has sparked scholarly debate, with various perspectives exploring historical, stylistic, and technological shifts.

One significant marker in defining this transition is the establishment of the tōken-kiwamedokoro in Genna two (1616), where appraisals were exclusively issued for old swords (kotō), reflecting a shift in focus towards authenticating older blades rather than newly forged ones (shintō). Alternatively, some scholars emphasize stylistic changes and advancements in steel production as key factors in distinguishing shintō swords. The emergence of shintō-jigane, characterized by notable changes in jigane composition, particularly around the Genna (1615-1624) and Kan’ei (1624-1644) eras, further delineates this period.

The end of the shintō era is often associated with the fukkotō movement, initiated by Suishinshi Masahide, which sought to revive old kotō-era forging traditions. This movement gained momentum around the An’ei era (1772-1781), marking a transition towards a renewed appreciation for traditional swordmaking techniques.