Genroku Shintō — The Forging Style of Japan's Peak Aesthetic Era

Genroku Shintō refers to a specialized periodization denoting the forging style centered on the Genroku to Kyōhō eras (1688–1736), as the third phase of the Shintō period following Keichō Shintō (1596–1615) and Kanbun Shintō (1661–1673).

The stylistic core of Genroku Shintō lies in the "culmination of the decorative treatment of the hamon." Whereas Keichō Shintō was founded on a bright, clear beauty in both the jigane and the hamon, Kanbun Shintō established an orderly beauty with shallow sori and compact, small kissaki. Genroku Shintō, following this trend, pursued still bolder variations in the hamon and a combined decorative effect of sunagashi, kinsuji, and utsuri within the blade. In particular, the "hataraki within the hamon," the decorative appearances such as sunagashi and kinsuji that appear inside the hamon, which the master smiths of Ōsaka Shintō excelled at, is the greatest technical highlight of Genroku Shintō.

Tsuda Echizen no Kami Sukehiro (1637–1682; main period of activity in the Kanbun to Enpō eras) and his tōranba (surging-wave hamon) represent the most important innovation leading the aesthetics of Genroku Shintō. Tōranba is a hamon with large undulations resembling great waves crashing ashore, with a large difference in height across the hamon, and with nie and nioi intricately intertwined at the crests of the waves. This hamon has the most dramatic visual effect and exerted a strong influence on swordsmiths in both Ōsaka and Edo after the Genroku period. Later, as Kamata Natae praised Sukehiro alongside Inoue Shinkai in Shintō Bengi, it became fashionable to temper tōran-midare in the early Shinshintō period.

The Kotetsu (Nagasone Okisato) school of Edo carried the forging style representative of Edo in the Genroku period. Kotetsu himself reached his peak in the Kanbun era, but his successor, Okimasa, the second generation, left dated works up to Genroku 3 (1690) and inherited the distinctly Edo aesthetic of "strong jigane (the quality of the jigane) and deep nie." Blades of the Kotetsu school, in contrast to the decorative hamon of Ōsaka Shintō, tended to compete on the texture of the jigane and the depth of the nie rather than the complexity of the hamon, and this contrast between east and west shaped the diversity of Genroku Shintō.

The compilation of the Kyōhō Meibutsuchō (1719) is an important cultural event that coincided with the height of the Genroku Shintō style. This catalogue of famous swords, compiled at the order of Tokugawa Yoshimune by Hon'ami Kōchū and others, recorded 274 famous swords and marks the institutional peak of the culture of sword appreciation in the Genroku period. After the Kyōhō Meibutsuchō, the system for evaluating swords came to be organized around the criterion of "whether or not a sword is recorded in the Kyōhō Meibutsuchō," and the framework of appreciation culture formed in the Genroku period continued through the late Edo period.