This sword is signed “Minamoto Moritsugu” (源盛次), a smith active in the early Edo period (17th century). Moritsugu belonged to a lineage of swordsmiths working under the prestigious Minamoto name, a title often granted as an honorific to skilled smiths of the era. His blades are known for their refined jigane (well-forged steel surface) and restrained suguha hamon (straight temper line), displaying the classical elegance valued in the early Edo period. Surviving works by Moritsugu are relatively scarce, but they show careful workmanship and a strong connection to the traditions of Hizen and Yamashiro styles that influenced many smiths of the time.
This example measures 58.3 cm and is mounted in a complete set of Imperial Japanese Navy officer koshirae, with all fittings bearing the same serial number. The gilt-brass mounts, sharkskin-covered scabbard reflect the standard regulation pattern, yet the presence of an Edo-period blade within such mounts demonstrates how family swords were adapted for service.