In the world of One Piece, Enma is a specific type of sword known as an Ō Wazamono grade sword. Ō Wazamono is the highest rank of sword classification, indicating exceptional quality and rarity. Enma holds significant importance in the Wano Country arc of the series.

Enma is a katana, a traditional Japanese sword with a curved, single-edged blade and a long grip that allows for a two-handed grip. It has a distinct hilt and guard design, reflecting the cultural aesthetic of Wano Country.

What makes Enma particularly notable is its unique ability to absorb and channel the wielder's Haki, which is a form of spiritual energy and power in the One Piece world. This ability amplifies the strength and intensity of the Haki used by the wielder.

Enma was previously wielded by Kozuki Oden, a legendary samurai and former ruler of Wano Country. After Oden's death, the sword passed into the possession of Roronoa Zoro, one of the main characters of One Piece. Zoro wields Enma alongside his other swords and utilizes its powerful Haki-absorbing properties in battle.