A Western-looking sword, Yoru is a cruciform and well-ornated weapon with a curved, single-edged, black blade—resembling an oversized kriegsmesser. It has a total length of well over two meters, being over a head taller than Mihawk (who stands at 198 cm) when placed on his back. While not in use, due to lacking a scabbard, Yoru is held upside-down against Mihawk’s back by two simple holding loops integrated into the man’s coat.

In the past, Mihawk was known as the “Marine Hunter”and had a reputation for being the rival of Shanks, one of the Four Emperors. His place of residence was Kuraigana Island, on which he served during the two-year timeskip as Roronoa Zoro’s master in his swordsmanship training. Alongside his former Warlord colleague, Crocodile, Mihawk created an organization known as the Cross Guild, with Buggy of the Four Emperors acting as the organization’s figurehead leader.