説明
Signature (Mei): Mumei Swordsmith: Attributed to the 下原(Shitahara) group School / Tradition: Shitahara school (Bushu / Musashi); Sōshū–Mino influenced workmanship Period / Province: Muromachi period / Bushu (present-day Hachiōji, Tokyo) Certificate: NBTHK Hozon(保存刀剣) Mounting: Shirasaya; metal habaki, 22.9 g Blade Length (Nagasa): 62.27 cm Curvature (Sori): 0.76 cm Mekugi-ana: 3 Shape: Shinogi-zukuri Jihada: Fine koto jihada with Shitahara traits; look for jorinmoku (如輪杢) whirlpool figure in places Blade Weight: 545.1 g (blade only) Habaki Weight: 22.9 g Saya Overall Length: 85.4 cm Motohaba / Motokasane: 2.816 cm / 0.728 cm Sakihaba / Sakikasane: 1.782 cm / 0.388 cm A koto katana certified NBTHK Hozon and attributed to the Shitahara group of Bushu (Musashi). Measuring 62.27 cm in nagasa with a gentle 0.76 cm sori, the blade presents a dignified shinogi-zukuri profile and a well-forged jihada praised in the listing. Three mekugi-ana reflect remounting over a long service life while maintaining healthy proportions. Shitahara blades often show steady forging with Sōshū–Mino influences. A hallmark to watch for is jorinmoku ( 如輪杢 )—small whirlpool-like figures in the steel surface—seen on representative works by Shitahara smiths. Swordsmith Background Shitahara is the historical smithing area in today’s Hachiōji City (Tokyo) . The school is said to have been founded by Yamamoto Norishige and prospered from the end of the Muromachi period into late Edo (late 16th–19th centuries). Shitahara smiths—known as Shitahara Kaji —first worked under the Hōjō clan. The celebrated Yasushige line begins with the first generation, originally signing Chikashige ; he adopted the character 「康」 (Yasu) from Hōjō Ujiyasu , changing his name to Yasushige . After the Hōjō were defeated by the Toyotomi during the Azuchi–Momoyama period, the Shitahara group served the Tokugawa as okakae kaji —official smiths retained by the feudal house—and continued forging through the Edo period. Many Shitaha
