The swordsmiths of 備前長船 (Bizen Osafune) from the latter part of the 室町時代 (Muromachi period) and their swords are collectively referred to as 末備前 (Sue-Bizen). Among them, many swordsmiths took the name 清光 (Kiyomitsu), including those with the common names 五郎左衛門尉 (Gorosaemon-no-jo), 孫右衛門尉 (Magoueimon-no-jo), 与三左衛門尉 (Yosazaemon-no-jo), 彦兵衛尉 (Hikoemon-no-jo), and 孫兵衛尉 (Magobei-no-jo). These swordsmiths, along with 祐定 (Sukesada), 勝光 (Katsumitsu), and 忠光 (Tadamitsu), are renowned as representatives of the Sue-Bizen school, with many of their works featuring relatively straight hamon (temper lines). In particular, 五郎左衛門尉 (Gorosaemon-no-jo) and 孫右衛門尉 (Magoueimon-no-jo) were highly esteemed and favored by many warlords of the 戦国時代 (Sengoku period).

This sword features a well-balanced width difference between the base and tip, with a slightly extended mid-sized tip. The blade is thick and robust, with a well-forged, tightly grained steel that includes a mix of small itame and mokume patterns, displaying a refined appearance with a faint utsuri. The hamon is a typical 清光 (Kiyomitsu) suguha, bright with a mixture of gunome and ko-gunome, featuring ashi and yo throughout. It shows prominent kinsuji and sunagashi activities, and the boshi is nearly a single piece with a rounded tip.

Despite being a work from the Muromachi period, it retains an impressive 8mm thickness and a rich, healthy blade. Although it has been shortened, resulting in the loss of its original signature, it remains in excellent condition. There is a forging flaw on the shinogi-ji on the ura side, but modern polishing techniques can almost completely restore it.

The blade appears hazy from years of maintenance with uchiko powder, but a cosmetic touch-up will restore its clarity. The sword is well-balanced with the center of gravity towards the hand, making it not only visually appealing but also easy to handle. As mentioned, it is recommended to repair the forging flaw and submit it for a 特別保存刀剣 (Tokubetsu Hozon Token) certification.

Bare weight: 753 grams.