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

　A kodachi is a short tachi (a sword made to be worn with the cutting edge down). While it is considered to have been worn on the waist with a tachi, its purpose of use is still unknown. According to the Kyoho Meibutsu-cho (a book of quality products in the Kyoho era), the name seems to derive from an "outlaw" called "Hachiya" who owned this short sword in the Momoyama period. Nagamitsu, a swordsmith of the Osafune school in Bizen no Kuni, actively produced swords for approximately 30 years after 1274. His style shifted from the hamon (blade pattern) with brilliant chojiba (a clove pattern) that resembled the style of his father Mitutada to the hamon in the suguha (straight) style that resembled the style of his son Kagemitsu. This kodachi has a jigane (ground metal) with a wood grain pattern with utsuri (a white misty formation that runs parallel to the hamon in the ground metal) and a brilliant hamon with gunomechojiba of the same length and lots of ashi (martensite crystals), which demonstrates Nagamitsu's typical style.