So far I only know of:
Japan Tool - http://www.japan-tool.com
Japan Woodworker - https://www.japanwoodworker.com/
Suzuki-ya - https://suzukitool.com
Tools from Japan - https://www.toolsfromjapan.com/store (though I am not exactly sure how long this store will continue to last as it seems to be closing?)
Iida Tool - http://www.japantool-iida.com
Hida Tool - http://www.hidatool.com
Wondering if anyone else has any sources not listed here. Thanks!