This guardless dagger (‘aiguchi’) was possibly made in the late 14th century when Japan was riven with civil war and two emperors were struggling for power. The blade itself is carved with characters that invoke Hachiman Dai Bosatsu, the Buddhist deity associated with war.

The blade was remounted in the mid 19th century in a scabbard of natural wood bark with metal fittings in silver, gold and shakudo, an alloy of gold and copper patinated to a rich black colour. The 16th-century warlord Toyotomi Hideyoshi famously described the colour of shakudo as that of ‘rain on a crow’s wing’. Some of the fittings are in the form of sprays of paulownia; others are in the form of phoenixes. Both features were associated with marriage: the phoenix represents long life and the pauwlonia good luck. It was believed that the phoenix would alight on the paulownia tree only during times of prosperity or as a signal of the arrival of a good or virtuous ruler. The phoenix was also a symbol of the emperor and the paulownia a symbol of the Tokugawa shoguns. At the time the blade was remounted, Japan was at peace but was struggling with a collapsing political system and with conflicts between supporters of the emperor and those of the shogun. There are curious similarities between the political state of Japan at that time and the troubles in the country at the time the blade itself was made.