The blade of this Japanese long sword (‘katana’) has the fake signature of Kanemitsu, a famous 14th-century swordsmith. The inscribed date has been altered to read ‘Embun nana nen, ni gatsu hi’ - ‘second month of the seventh year of the Embun period’, which is equivalent to 1362. It is obvious that the final two characters of the signature have been altered, as have the first two of the date. Tellingly, the Embun period of Japan’s brief northern dynasty lasted only five years (1356-1361), not seven. The characteristics of the blade and the style of the original signature suggest that the swordsmith was either Sukenaga (1795-1851) or Sukekane of the Yokoyama school in Bizen. The only historical period of seven years or more that fits this hypothesis is the Tempo period (1830-1844), which would make the actual date of the blade 1836.

The blade is carved on one side with a dragon and a Buddhist heavenly jewel, and on the other side with the ‘bonji’ (debased Sanskrit character)) for the deities Aizome Myo-o and Fudo Myo-o, along with a stylised Buddhist lotus throne (‘renge’). The tempered edge (‘hamon’) shows the distinctive style of the 19th-century Yokoyama school, with the pattern sloping gently towards the hilt of the blade.