A Japanese tantō bearing the single-character mei “Ichi” (一), measuring approximately 18 cm in length. The piece is fashioned in the highly distinctive Osoraku-zukuri, with the exceptionally long kissaki extending over half of the overall length. The jihada is a very fine and tightly forged ko-itame, while the nakago retains prominent horizontal yasurime.

Osoraku-zukuri is one of the rarest and most distinctive forms found among traditional Japanese short blades. Its defining feature is the unusually low position of the yokote, resulting in an exceptionally long kissaki that can occupy more than half of the entire length. The form is traditionally associated with the famous 16th-century Suruga-Shimada smith Sukemune, whose remarkable work became the prototype for this unusual style. The distinctive form attracted considerable attention and was subsequently reproduced by smiths in later periods.

The unusual sugata, refined jihada, and single-character mei suggest a Sue-Koto work of the late Muromachi period, most likely from the Suruga-Shimada tradition, dating approximately to the second half of the 16th century. The combination of an “Ichi” mei and exceptionally rare Osoraku-zukuri form makes this a particularly unusual.