Katana by Koyama Munetoshi, a smith of Shirakawa in Mutsu province, whom the original seller places in the family of Koyama Munetsugu, one of the great masters of late Edo. The tang, intact according to the photographs and with a single mekugi-ana, bears the signature 陸奥白川住固山宗俊 (Mutsu Shirakawa-jū Koyama Munetoshi) on the omote and the date 文久三年八月日 (Bunkyū sannen hachigatsu hi) on the ura. It is a wide, thick blade: 71.85 cm nagasa, 1.4 cm sori, 3.28 cm motohaba and 0.91 cm motokasane; the original seller describes a slightly extended kissaki. According to the seller, the jigane is a well-forged ko-itame with ji-nie and chikei, and the hamon a bright gunome with abundant ashi; the backlit photographs show that gunome along the whole blade. The seller states it is free of any flaw in the ji or the ha. It comes with an uchigatana koshirae with a reddish-brown ishime-lacquered saya, matching fittings on a spider-web theme and a large kojiri with silver tendrils, together with shirasaya, tsunagi and a gold-foiled copper habaki. It is accompanied by the NBTHK Tokubetsu Hozon paper (2009) and a 1984 certificate from another association rating it an outstanding work.