Kaiu Forge (TCG)

The Kaiu Forge crafted each blade with three types of steel: durable hagane for the blade's edge, flexible shingane for its core, and medium kawagane as a skin between the two. Each type required a different manner of preparation that was overseen by a specialist. Many Kaiu smiths dedicated their entire life to a single step of the process, such as polishing, sharpening, or tempering.