Many existing examples of this particular weapon are associated with the Sōhei or Yamabushi (warrior monks), who also adapt other agricultural tools as weapons although samurai are also pictured as using ono in wood block prints. Ono that were specifically designed for military use are of extreme rarity.
The weapon version of the ono is described as having "a very large head with a very convex cutting edge and a large scroll-shaped peen opposite it. It has a sheath covering only the edge of the blade. The entire length is nearly six feet".