Specifications:

• Sori (Curvature): 0.8 cm
• Hamon (Temper Line): Suguha, characteristic of Ko-Mihara school
• Blade Length: 60.8 cm
• Period : Nanbokucho (650 years ago)
  
• Province : Bingo 備後
• Certificate : NBTHK Tokubetsu Hozon Token
• Koshirae

Historical Context: This Katana is attributed to the Ko-Mihara school from Bingo Province, Japan, active during the Nanboku-cho period in the 14th century. This era was marked by significant political unrest and the rise of regional powers, which heavily influenced the development of Japanese swordsmanship and smithing techniques.

The Ko-Mihara school is renowned for its Yamato-style craftsmanship, characterized by a straight and elegant suguha Hamon and a distinct 'Mihara Boshi' at the blade's tip. Founded by Masaie, the school includes notable smiths like Masahiro who continued the tradition of exceptional blade-making. These swords were favored by the samurai for their reliability, sharpness, and craftsmanship, reflecting the martial needs and aesthetics of the time.

Ko-Mihara blades are significant for their contribution to the evolution of Japanese sword-making, embodying the artistry and skill of their era.