At Tokyo's Meiji Gakuin University, professor Keiko Tanaka has been teaching classes with half as much lighting as usual and with less reliance on computers and other electricity-hogging tools. She now often gets out her chalk and eraser to use the blackboard.

But with tsunami-torn Japan's electricity system struggling, she wonders whether her fellow citizens will commit to the level of energy savings the nation needs.

(Related: Japan Tsunami: 20 Unforgettable Pictures)

"Japan is a country where 18-year-old girls take the elevator to go up a single flight of stairs because they don't want to sweat," she said. "It is a country where most toilet seats are heated, and there is an electric noisemaker in the women's toilet to mask the noise.