From Wakeido, a product introduction.

This is a sword attributed to Narie of Bizen from the Nanbokucho period(AD1350).

Sword Mumei（unsigned） Nariie

Certif [N.B.T.H.K] Jyuyo Touken

Measurements Length 71.4 cm Sori (curvature) 15 mm Mekugi-ana (peg hole) 1
MOTO-HABA (base width) 32.5 mm SAKI-HABA (tip width) 25 mm MOTO-KASANE (base thickness) 7 mm

Province Bizen(Okayama)

Period Nanbokucho period

Shape Shinogi-zukuri, iorimune, wide mihaba with little difference between base and tip width, slightly thick kasane, shallow overall sori with a belly curve, large kissaki

Hada (forging) Itame with mokume and nagare textures mixed, somewhat prominent hada, ji-nie well attached in places, frequent chikei lines, faint utsuri appearing

Hamon (temper) Generally low tempered line, small tare mixed with gunome, a few sharp-pointed teeth-like elements, komasaari (small foot) present, nioigachi (prefers nioi), kansuji present, occasional niokuchi depression

Boshi (tip temper) Midare-komi with kansuji, on the omote the point is swept and looks yakitsume-like, on the ura it turns back shortly with a small round tip

Carving Bo-hi drilled through on both sides

Nakago (tang) O-suriage (shortened), saki-kiri, yasurime kiri


Commentary
Nariie of the Osafune school in Bizen Province is said by one account to be a descendant of Keishu (Mitsutada’s younger brother) and was active in the late Nanbokucho period as one of the smiths classified among those with kosori school. However, mei-kanki records list somewhat earlier years such as Bunwa through Koan, and based on style and mei characters a connection with Kanemitsu is also possible, requiring further study. His skill is comparable to Masamitsu of the Kanemitsu group from the same era.
This sword displays the Nanbokucho-era style with a wide mihaba and large kissaki. The jigane shows itame forging with somewhat prominent hada and frequent chikei, producing irregular areas of changed iron that appear thick in places. The hamon is low notare and mixed gunome, demonstrating the distinctive features of Nariie belonging to the Kosori school type. Above all, its heavy, majestic presence and the varied, striking forging make this an outstanding piece.