[UPDATE: Shimanekan is closed for renovation, and will reopen in February 2018.] Sake and foodstuffs from Shimane-ken, in the far northwest corner of Honshu, can be purchased here. The attached restaurant (called Mondo) serves good regional cuisine and sake.
This book will introduce you to more than twenty of Japan's favorite specialty foods that are less well known abroad, along with a guide to the best places in Tokyo to try them and expert tips on what to order. From Bento.com.