A Mantetsu Katana (興亜一心満鉄作)

For collectors of Second World War memorabilia, this is a katana worth serious consideration. Signed Kôa Isshin – meaning “Asia, one heart” – this blade embodies the fierce patriotism that defined Japan’s wartime identity. Mantetsu steel was developed at the Dairen Manchurian Railroad Factory from September 1937, and the ideological phrase “Kôa Isshin” was adopted from 1939. Metallurgical analysis has confirmed the steel is exceptionally pure, close to wrought iron in composition.

Dated to the spring of 1943, this is one of the later examples from the factory. The hamon is a thin, laser-precise hoso-suguha – the hallmark of Mantetsu production – running cleanly along the blade from base to tip. The sword carries well in hand and its cutting-edge length is typical of guntô, the military-mounted swords of the era. The nakago is ubu, fully original and unshortened, with the date inscription intact.

A modern custom koshirae with a warrior and dragon theme was made especially for this sword. The red-vermillion lacquered saya is a striking complement to the blade’s austere character, reflecting the passion the sword itself represents.