National Treasures & Important Cultural Properties
of National Institutes for Cultural Heritage, Japan

Rai Kunimitsu, active at the end of the Kamakura period (1185-1333), was a swordsmith of the Rai School in Kyoto. Even within the Rai School, he made a wide range of swords, from slender, classical blades to broad, magnificent ones. His temper lines also varied from the basic straight line (J., suguha), characteristic of the Rai School, to narrow straight (J., hoso-suguha) and wide straight (hiro-suguha) lines.
This sword displays Rai Kunimitsu's characteristic features: the blade is broad, the temper line is wide and straight, crossed by short streaks (J., ashi, literally, "legs") and dots (J., yô, literally, "leaves") toward the tip of the blade. The blade was originally long, but in the Edo period (1615-1868), the swordsmith Umetada Myôjû (1556-1631) shortened its tang and made it into the katana form.