Japan Woodworker too:
http://www.japanwoodworker.com/dept.asp?s=JapanWoodworker&dept_id=13083If you insist on learning to sharpen these things (
), they have the kind of files it takes to do it. I mostly use them with care, and toss 'em when they're shot. Look for the kind with replaceable blades. I have a couple I've been using at work without sharpening for 4-5 years now. Good ones are incredible.