The opposite of concave is convex! The Messermeister Mu Fusion 6.5" Dot Knife uses this principle to assist in lowering the friction coefficient of tension that exists because many fruits and vegetables are naturally attracted to the side of the blade. Breaking the tension is tantamount to a more efficient cut, not to mention that this Santoku with it's beautiful linen textured black handle looks like a piece of modern art. Oh, and did we forget to say it has an AUS 6 high carbon steel blade that is really really sharp!