The retail giant 7&i Holdings reported an 8 percent increase in sales for the first half of fiscal 2011 over the previous year. It was a new record and clearly driven by the company's 7-11 convenience stores. They aren't the only ones. The three other main CS chains — Family Mart, Lawson and Sunkus/Circle K — have also reported strong earnings, the result of what the Asahi Shimbun calls a "better opinion" of convenience stores in the wake of the March disaster.

Because there are so many convenience stores, they tend to be in closer proximity to people's homes than larger retail operations, so during that anxious period when people did not want to stray too far from their homes and loved ones, CS became a sort of lifeline. As a result, demographics that previously didn't patronize convenience stores, such as housewives and the elderly, came to rely on them more and more, and in the process also came to appreciate their distinctive merchandising schemes.

This success has given the industry a sense of purpose, and all four big CS chains have announced plans to open as many stores as possible over the next year or so. According to the Japan Franchise Association, as of March 2011 there were 45,769 convenience stores in Japan. The industry itself, according to the Asahi, believes that the "saturation point" for convenience stores in Japan is 50,000, though some analysts say that due to the rise in single-person households, which is exactly the sort of scenario that benefits CS, the market may be able to absorb even more.