A ko-tanto
The blade 15th century, the mounts 19th century
The blade of hira-zukuri form, irregular gunome-ha of nie and nioi, with kaeri fukai, the nagako with one mekugi-ana, signed Shigemasa; koshirae: the saya of ribbed roiro-nuri; the en-suite fittings consisting of tsuba, kozuka, split kogai and fuchi-gashira of shakudo nanako, inlaid with lobsters and flower buds in gold and copper takazogan in Ishiguro style; the menuki of copper, in the form of lobsters.
The blade 23.5cm (9¼in) long.