What makes the Shusui a Kokuto, or black blade, in One Piece lore?
Updated Feb 2026
In the One Piece universe, a Kokuto is a blade that has been infused with its wielder’s Haki over countless engagements until the steel itself permanently transforms, turning black and increasing in grade. The Shusui reached this status under Shimotsuki Ryuma, the legendary swordsman of Wano Country, centuries before Zoro acquired it. Only two confirmed Kokuto exist in the story — the Shusui and Yoru, Dracule Mihawk’s great sword. This makes the Shusui exceptionally rare within the lore and a highly sought-after replica among collectors. Our reproductions honor that narrative significance with a darkened blade finish and flame-pattern hamon that visually distinguish it from standard polished katana replicas.