From there, chokutō was brought to Japan by way of Korean Peninsula and China in the Han Dynasty times.[8][9] It was created before the development of differential tempering in Japanese swordsmithing. Chokutō typically come in hira-zukuri and kiriha-zukuri tsukurikomi (blade styles) which make them very distinct from later tachi and katana which rarely use these forms. Swords of this period are classified as jōkotō and are often referred to in distinction from Japanese swords.[3]