After I finished sharpening a less sharp cooking knife on a whetstone, I remembered the fruit knife I bought when I was 18yrears old living alone in Tokyo.
This fruit knife became completely dull, and cannot be used even as a paperknife now. I sharpened the knife on the whetstone.
After sharpening, I cut a piece of paper to test the sharpness.
Sharpening Fruit knife on a Whetstone
(this stone is a natural stone from an island in Japan).
Tasting the sharpeness with a paper.