This long sword is dated from 1781 – 1788 by the museum catalog, but the reason is not clear. It is possible that the date was derived from the signature in the past, however it has become indistinct throughout the years, and so can no longer be read. It is mounted in tachi fashion with two ashi making it possible to wear the sword edge down, unusual for katana, but common for tachi and swords mounted to be worn in battle. The scabbard is of lacquered wood in black and red. The fittings are of shakudo with gold crests. The tsuka is wrapped with a black silk cord. The blade is 73 cm long and has no grooves on either side. The hamon (temper line) is narrow and straight on the deeply curved blade.
(Commentary by Rob Nalewajk)