Juyo Rai Kuniyuki katana

Jūyō Tōken – 61st Designation

Date of Designation: October 20, Heisei 27 (2015)
Sword Type: Katana – Mumei (unsigned)
Attribution: Rai Kuniyuki

Measurements:

• Nagasa: 68.7 cm

• Sori: 1.7 cm

• Motohaba: 2.75 cm

• Sakihaba: 1.9 cm

• Kissaki-nagasa: 3.2 cm

• Nakago-nagasa: 18.4 cm

• Nakago-sori: slight

Shape (Katachi):

Shinogi-zukuri, iorimune, with a standard mihaba, and almost no difference between the width at the base and the tip. Although suriage, the blade retains a strong koshi-zori, and a slight increase in sori toward the tip, with a chū-kissaki.

Kitae (Forging):

A tight itame-hada with thick, fine ji-nie throughout.

Hamon:

A suguha-based pattern mixed with ko-chōji and ko-gunome, showing hotsure and fine chikei within the ha. A faint nie-utsuri appears across the ji. In parts, chōji-ashi stand out, and the blade is covered with ko-nie. In some sections, clusters of particularly bright and coarse nie appear, accompanied by kinsuji and sunagashi.

The blade exhibits frequent hakikake along the hamon.

Bōshi:

A very shallow notare-gokoro, turning into a small rounded kaeri (komaru).

Nakago:

Ō-suriage, with a kirijiri tip. Yasurime are katte-sagari. Four mekugi-ana are present. The blade is mumei.

Additional Activities:

Nijūba and kuchigaiba can be observed, with ashi and yō present within the ha.

Explanation:

Kuniyuki is regarded as the de facto founder of the Rai school. Although only a single example of a tantō attributed to him is securely known, a relatively good number of his signed tachi survive. None of Kuniyuki’s works bear dated inscriptions, but since a blade by his son, Niji Kunitoshi, bears a date of Kōan 1 (1278), the generally accepted dating of Kuniyuki’s active period to around the Kōgen era (1256–1257) is considered appropriate.

Among Kuniyuki’s tachi, there is variety: some are slender and graceful, others standard in proportion, and still others are wide and imposing.

This blade features a refined and tightly forged itame-hada with a clear nie-utsuri across the ji. The hamon is based on suguha with small chōji and gunome elements interspersed. The boshi smoothly transitions into a small rounded form (komaru), closely matching the characteristic features of the Rai school’s work.

Particularly noteworthy are the ancient-feeling chōji elements that appear prominently within the hamon, reinforcing the attribution to Kuniyuki. The hamon displays sections where especially brilliant nie sparkle vividly, while the overall ji and ha are clear, bright, and crisp. The blade remains in excellent and healthy condition overall.