I tried a few cheap ceramic knives from Harbor Freight several years ago. They were indeed sharp, but they were very fragile and neither of them lived more than a few months in my kitchen. Kyocera blades are much better, although they still have their uses and their limits: no chopping, no bones, no dishwashers, and no children.
Later on I got a genuine Kyocera utility knife, which did good service until my daughter used it and violated rules 1, 2 and 4. When she showed me what happened, the insanely-sharp blade had two enormous divots chipped out of it, and the carefully-packed knife went in the trash.
This video shows how they’re made from ore to blade, including the final test of sharpness in which the master sharpener slices his own finger. I wouldn’t mind seeing that level of quality control on this side of the Pacific sometimes, even though it’s more than a little creepy.