Bento culture is unique to Japan partly because of differences in the use of water in cooking between Japan and other countries, according to Nobuo Harada, professor emeritus in the history of food culture at Kokushikan University in Tokyo. "Japanese cuisine often uses grilled fish, and food simmered in dashi broth," he said. He compared this to Western meals, which "are not good to carry out because they have a sauce poured over them, and thus have a lot of juice." Across the wider Asian region, Bento has not taken hold because, for example, Chinese cuisine includes many meals cooked in sauces, Harada said. Southeast Asians, meanwhile, are amply served by food stalls, so Bento has not caught up there, he explained. Fine-looking Bento is considered to have developed in Japan during the Edo period (1603-1867). "Citizens prepared fancy-looking and tasty bento for enjoyment during viewing of the cherry blossoms or in an interval of a theatrical performance," Harada said. Many people abroad make Bento on a routine basis these days. He said that Thomas Bertrand from France, who operates Kyoto-based bento box maker Bento & Co., sells up to 100 units daily, mainly in Europe and the U.S. Top-notch chefs use bento boxes at restaurants and hotels overseas. According to Bertrand, two-tiered or partitioned bento boxes are becoming very popular abroad as they are rarely available outside Japan. In France, the word bento appeared in a dictionary for the first time more than ten years ago and is becoming more commonly used in everyday life, he says.