Editing Japanese sword (section)

====Sōshū school====
[[File:Katana - Kiriha Sadamune.jpg|thumb|300px|A Sōshū school ''katana'' modified from a ''tachi'', ''Kiriha Sadamune'', by [[Hikoshiro Sadamune|Sadamune]], son of [[Masamune]]. 14th century, Kamakura period. Important Cultural Property.]]
The Sōshū school is a school that originated in [[Sagami Province]], corresponding to present-day [[Kanagawa Prefecture]]. Sagami Province was the political center of Japan where the [[Kamakura shogunate]] was established in the Kamakura period. At the end of the 13th century, the Kamakura shogunate invited swordsmiths from Yamashiro school and Bizen school, and swordsmiths began to gather. [[Shintōgo Kunimitsu]] forged experimental swords by combining the forging technology of Yamashiro school and Bizen school. [[Masamune]], who learned from Shintōgo Kunimitsu, became the greatest swordsmith in Japan. From the lessons of the [[Mongol invasion of Japan]], they revolutionized the forging process to make stronger swords. Although this forging method is not fully understood to date, one of the elements is heating at higher temperatures and rapid cooling. Their revolution influenced other schools to make the highest quality swords, but this technique was lost before the [[Azuchi–Momoyama period]] (''Shintō'' period). The Sōshū school declined after the fall of the Kamakura shogunate. Their swords are often characterized by a shallow curve, a wide blade to the back, and a thin cross-section. There are irregular fingerprint-like patterns on the surface of the blade, the ''hamon'' has a pattern of undulations with continuous roundness, and the grains at the boundary of the ''hamon'' are large.<ref name="rekishi200972">''歴史人'' September 2020. pp.72–73. {{ASIN|B08DGRWN98}}</ref>