【中級編】両刃包丁の研ぎ方 【Intermediate Level】 How to Sharpen a Double-Edged Knife Whetstones Used Rough whetstone 400 grit Medium whetstone 1000grit Fine whetstone 6000 grit Extra fine whetstone 13000 grit #knife #sharpening #sharpener #asmr #研師Ryota