You can always check with Melvin Ang, the south East asia distributor if more info is required, and no Koetsu are not made in China, the late Suguno passed his know-how to his sons before he passed away....check with Melvin, he visits the Sugano household ever now and then.
http://home.pacific.net.sg/~angmelvin/
http://home.pacific.net.sg/~angmelvin/