Hi.For all those interested in japanese natural stones here is a site which I hope you will find useful. http://www.japan-tool.com I have been a customer but whether you are looking to buy or not, this is a source of reliable and in depth knowledge on the subject which is,in my experience,rare.The name of the site's owner is So.He is a native japanese speaker who is comfortable in english and a good guy who loves sharing his enthusiasm.I think that up to now most of his customers have been woodworking tool types but when we last met(we both live in Sydney) I suggested that I mention his site in a straight razor forum so here we are.
Ron