Zawashi

A weapon that emerged on Fugawa (Iwahfuah 0924), a world colonized by Terrans of Japanese descent early in the Rule of Man. The humans there earned much respect from the expanding Hierate, and so were afforded more liberty and involvement in Aslan society. The zawashi, styled after feudal Japanese weapons, became the standard dueling weapon among humans of the region. This, and other dagger-like weapons, are used only one at a time and not in pairs.

Source: Imperial Lines 2, Mike Mikesh