People don't come to Shinshu Osake Mura for the atmosphere, or the music (there isn't any). There aren't even any chairs. The reason to visit this hole-in-the-wall, standing-only sake bar, located on the ground floor of one of Shimbashi's most ancient office buildings, is the great sake list.
Thirty or forty varieties are poured at any given time, including plenty of seasonal, limited-edition specials. Most are priced at either Y300 or Y500 for a decent 110ml pour - a major Tokyo sake bargain. It helps a lot if you can converse with the enthusiastic bartender in Japanese - he's eager to offer suggestions based on your tastes, and he hasn't steered us wrong.
Sake-friendly snacks - heavily tilted towards the salty end of the flavor spectrum (smoked tofu, spicy beef tongue), are Y300 each. If you want a break from nihonshu, the bar also serves over a dozen Japanese craft beers in bottles and cans, plus one or two on draft, starting at around Y240.
There's also a retail shop in back of the main bar where you can pick up beer and sake to take home.