Tatsuo Aoki's low-key Tokyo bar, Popeye, has become a destination for beer fanatics from around the country. They make the pilgrimage to sample Hokkaido ales and Shizuoka stouts, or for an impromptu lecture from Aoki on hops and yeast.

He's part of a nationwide uprising against the staggering blandness of local beer. Four beverage behemoths dominate the market, all promoting pilsner-style lagers that account for more than 95 percent of the suds sold. It's a bit like sidling up to a bar in 1980s Milwaukee: Miller or Budweiser?

Tastes are changing though. Craft beer is gaining popularity across the country through the efforts of people like Aoki, much like it has in North America and Europe. The four giants — Asahi Group Holdings Ltd., Kirin Holdings Co., Suntory Holdings Ltd. and Sapporo Holdings Ltd. — are experimenting with alternative brews too as they face a slide in consumption. The competition is changing the market and beginning to produce beer drawing acclaim around the world.