Koto Middle of Kamakura period (Kougen era/circa 1256) YamashiroLength of cutting edge 73.6cm Curvature 2.2cm Width of base 29.1mm Width of Yokote 20.5mm Thickness of base 7.0mm
NBTHK(Hozon)certificate
Polish and Sayagaki written by Ono Koukei (living national treasure)