Japan's convenience store chains chase elixir of growth across Asia

TOKYO -- It's 50 years since Kenji Yamamoto opened the doors at what would become part of the fabric of Japan: the country's first modern-day convenience store. But 50 years from now, Japan's population is projected to shrink by close to a third, and the fate of a multibillion-dollar industry will hang on how its big players negotiate essential growth overseas.