Antique Japanese Katana by Osafune Kiyomitsu — Signed and Dated August 1560 (Eiroku 3)

The tang is fully signed 備前国住長船孫右衛門尉清光 — read Bizen Koku jū Osafune Magōemon-no-jō Kiyomitsu (“Kiyomitsu, holder of the Magōemon-no-jō title, resident of Osafune in Bizen Province”). The date on the reverse remains 永禄三年八月日 (a day in the eighth month, Eiroku 3 = 1560 CE). The deep, legible mei and precise date firmly place the blade in the Sengoku Jidai, the summer of Nobunaga’s Okehazama campaign.

The blade displays a robust battlefield sugata with deep torii-zori, an active suguha-gunome midare hamon in nioi with nie, and itame jihada with areas of mokume. The chū-kissaki shows a defined yokote and a boshi with hakikake tendencies. It is in presentable polish; natural age marks are consistent with a mid-16th-century sword.

Mounted in WWII officer’s guntō koshirae (leather-covered wooden saya, brass tsuba/fittings), the sword carries compelling dual-era history. A signed and dated Bizen Osafune work of this quality is a strong candidate for NBTHK Hozon submission.

Details

• Smith/School: Osafune Kiyomitsu (Bizen Province, Osafune school)

• Signature (mei): 備前国住長船孫右衛門尉清光 (Bizen Koku jū Osafune Magōemon-no-jō Kiyomitsu)

• Date (uramei): 永禄三年八月日 (August 1560)

• Era/Region: Muromachi period, Sengoku; Bizen (modern Okayama)

• Sugata: Shinogi-zukuri; deep torii-zori

• Hamon: Suguha-gunome midare; nioi with nie activity

• Jihada: Itame with mokume; possible utsuri

• Kissaki: Chū-kissaki; boshi with hakikake

• Nagasa: 23.5" blade, with hilt and scabbard 35"

• Condition: Presentable polish; strong hamon; light age-consistent pitting/oxidation

• Mounts: WWII guntō fittings (complete and functional)

• Includes: Blade signed/dated 1560; wartime mounts; research notes; NBTHK eligibility noted; insured shipping available

Item Label

Katana by Osafune Kiyomitsu, August 1560
備前国住長船孫右衛門尉清光／永禄三年八月日

Japan (Bizen Province), Muromachi period, 1560 (Eiroku 3)
Forged steel; shinogi-zukuri with deep torii-zori; suguha-gunome midare hamon; itame jihada with mokume
Mounts: WWII officer’s guntō koshirae
Dimensions: Nagasa 23.5" blade, with hilt and scabbard 35"

Museum Card

Katana by Osafune Kiyomitsu
備前国住長船孫右衛門尉清光／永禄三年八月日

Osafune school, Bizen Province, Japan, 1560 (Eiroku 3)
Forged steel blade; shinogi-zukuri; suguha-gunome midare hamon; WWII guntō mounts
Dimensions: Nagasa 23.5" blade, with hilt and scabbard 35"

The tang bears a full signature identifying Kiyomitsu with the court title Magōemon-no-jō and residence in Osafune, Bizen. Dated to August 1560, the blade combines robust battlefield form with refined Bizen workmanship—active midare hamon, clear itame jihada, and a poised chū-kissaki—later remounted for military service in the 20th century.