Katana Abyssal Butterfly Hitatsura Hamon Kairyū Kagechō Koshirae 淵蝶 FS A black sageo (黒下緒) is

A black sageo (黒下緒) is traditionally tied to the kurigata

finished with a refined blackened patina (煮黒仕上げ)

preserving the natural character of the material and highlighting the timeless beauty of traditional metalwork

Menuki (目貫): Crafted from hakudo (白銅)

with a hardened steel core between softer outer layers

Katana Abyssal Butterfly Hitatsura Hamon Kairyū Kagechō Koshirae 淵蝶 FS A black sageo (黒下緒) isHitatsura Hamon Full Tang Shinken () Abyssal Butterfly Katana: TangGu () Maru Blade () + TangGu () Kairy Kagech Koshirae () This katana is hand forged (Tezukuri ) from high carbon modern steel () in the Maru zukuri () style. The blade is clay tempered (yaki ire ) to produce a Hitatsura hamon (full temper pattern ) that spreads dynamically across the surface, symbolizing untamed elemental energy. The koshirae features a maru gata tsuba () forged from