A Japanese tantō bearing the signature Bishu Osafune Sukesada (備州長船祐定), measuring approximately 24.3 cm in length. It features a restrained suguha hamon and a clearly defined itame jihada.

Sukesada was one of the most prominent smith names of the Osafune school in Bizen Province, flourishing particularly during the late Muromachi period (15th–16th centuries). Multiple generations worked under this name, producing pieces ranging from practical wartime arms to finely crafted works. The Sukesada lineage remains one of the most representative traditions of Sue-Bizen swordmaking.

It is mounted in a custom-made oversized Imperial Japanese Navy dirk mounting, indicating that the blade was privately selected by its owner rather than being a standard-issue weapon.