Mottainai is not an economical concept," says Hiroyuki Torigoe, a sociology professor at Waseda University in Tokyo. "It's a mentality." When Japan was a developing country enamored of American consumption and consumerism, Japanese people thought mottainai was outmoded, says Yukiko Kada, a former professor of environmental sociology who today is governor of Shiga prefecture. Now, Japanese people are rediscovering a desire to seek "spiritual and mental satisfaction" because their basic material needs are largely fulfilled, she says. "The environment has drastically changed," says Kada. "Twenty or 30 years ago there were many fish in lakes and rivers. But that has changed drastically and Japanese have started to think, 'Where have my fireflies gone?'" With luck and some mottainai, they'll soon be back.