Tachi Sword (signed Rai Kunitoshi)

A Rare Irregular Temper Line by Rai Kunitoshi

The Tachi Sword (signed Rai Kunitoshi) (太刀〈銘来国俊〉) is a Kamakura-period tachi by Rai Kunitoshi, location not disclosed (private collection), which in 1952 was designated a National Treasure.

The Agency for Cultural Affairs records one blade 72.1 centimetres long with a curvature of 2.4 centimetres and 2.7 centimetres wide at the base, first designated under the old system in 1941.

According to the Agency, the style of its signature suggests it was made in the Shoo and Einin eras (1288 to 1299).

The Blade

According to the Agency, it is ridged with a roof-shaped back, strongly curved near the hilt with a firm base and a small point. The steel shows a tight fine grain with crystals and a crystalline reflection.

The temper line is a narrow straight line mixed with small cloves and many legs, becoming more lively towards the middle, with small hip-temper effects on both faces. The tang is unaltered, with one peg hole and a three-character signature; the blade is 1.8 centimetres wide at the tip, with a point of 2.7 centimetres and a tang of 19.7 centimetres.

What to Look For

The Agency notes that Kunitoshi excelled at straight temper lines but occasionally made irregular ones; this is a masterpiece of the latter, carefully planned, with refined steel that sets off the temper line.

The Agency calls it a beautiful and elegant sword.

Visiting the Tachi Sword (signed Rai Kunitoshi)

It is privately owned, and no official information on viewing could be found.