Usuba

Designed for vegetables, the usuba is a single-bevel, thin-edged knife. Although the steel is often the same type and hardness as that used for a tough deba, the thin edge makes it much more delicate and better for vegetable work. 

Like several other single-bevel Japanese knives developed during the Edo period, two main styles exist: the Kanto -- developed around Tokyo -- and the Kansai -- from Osaka and Kyoto. The Kanto-style blade is square tipped with a spine that either ends in a pointed corner or a rounded tip. The Kansai style, also called a kamagata usuba because it looks like a sickle (kama), has a straight edge and a spine that curves down to meet at the tip.