Wiki-Small blade (Koba)

This term refers to a blade with an angled structure toward the tip of the blade. The main purpose is to prevent chipping by making the cutting edge obtuse while maintaining the overall thinness of the cutting edge. A blade that is even thinner than this small blade is called an ito-ba (ito blade).

Related websites
Mastering Japanese Knife Sharpening: Techniques & Tips | KIREAJI