Accompanied by a certificate of registration as Tokubetsu Juyo Token [Especially Important Sword], no. 263, issued by the Nihon Bijutsu Token Hozon Kyokai [Society for the Preservation of the Japanese Art Sword] at the 7th Tokubetsu Juyo Shinsa on November 20th 1980.
In old documents it is recorded that Sadazane was the son of Ko-Ichimonji Munetada and was active around the Hoji (1247-1249) era, but many of his existing blades have hamon of komidare strong in nie with no utsuri, and thus appear to be earlier than the documented works of Munetada. It seems more probable that he was one of the Ko-Bizen smiths. This tachi is Ubu (with possible slight machi-okuri) and of elegant form with a deep curve, fumbari and ko-kissaki. The jigane has prominent itame hada with much ji-nie and jifu, at first sight resembling the work of the Ko-Aoe School, and the suguha hamon with komidare and stretches of nijuba all combine to evince the ancient dignity of the swordsmiths' craft