How do I keep a Japanese kitchen knife sharp?

Keeping a Japanese knife sharp comes down to four habits: sharpen on a whetstone when the edge slows down, realign the edge gently between sessions, keep your stone dead flat, and dry the blade the moment you finish so it never sits wet.

Most home cooks only need a medium grit to start. At Knives and Stones the safest beginner anchor is the in-stock Naniwa Chosera 1000, ideally as part of a 400/1000/3000 ladder, plus an Atoma diamond plate to keep the stone flat. A flat stone is the difference between a knife that gets sharp and one that does not.

Care and sharpening are one system: a freshly sharpened edge still rusts if you leave the blade wet, and a neglected stone gives you a rounded, uneven edge. The four spoke pages below take each step in turn.