Every now and then you come across something so good it redefines your view on a subject.
Watanabe knives fit that description imho.
I have been using Wustoff Classics for the last 20 years and have maintained the edges with an edge pro sharpener, so that is a reasonable benchmark for comparison.
The Wustoff is to Watanabe what a Volkswagon is to an Aston Martin. The Wustoff is typical of high end German kitchen knives... heavy forged blades made from stainless steel with a fairly obtuse angle. There is no point decreasing the cutting edge angle or sharpening to a scalpel edge because the steel (with a rockwell hardness number of 56-58) simply isn't hard enough.
The pro series Watanabe blades are hand made by a sixth generation blade smith from a family heritage dating back to the age of the Samuri. The blades are a sandwich of Hitachi YSS (Yasuki specialty steel) encased in a stainless sheath. The cutting edge has a rockwell hardness number of 65-66, meaning it about 4x the hardness of your best German kitchen knives.
I can tell you that if you start with an equal level of sharpness, then after a period of use long enough to reduce the Wustoff to little better than a butter knife, the Watanabe is still sharp enough to shave your arm hair.
The best bit is that because you are buying direcrtly from the blade smith, they are no more expensive than Henkells, Global, Wustoff et al, priced at your local kitchen warehouse.
http://www.kitchen-knife.jp/pro/petite.htm