In Kate Elwood's last column of 2011 for The Daily Yomiuri she looks at the cultural associations with western and eastern staples, bread and rice:
Both bread and rice symbolize livelihood, as can be seen in a variety of phrases such as "earn one's bread," "know which side your bread is buttered on" and "take bread from someone's mouth," as well as meshi no tane ("rice seed": a means of living), meshi ga kuenai ("cannot eat rice": cannot make a living), and fude ippon de meshi o kuu ("eat rice by one ink brush": make a living as a writer). "Eating the bread of idleness" also corresponds nicely to muda meshi o kuu, to eat useless rice, which means to be unproductive. Bread and rice also both signify a communal experience. The idiom "break bread together" signifies sharing a meal, similar to onaji kama no meshi o kuu, to eat from the same rice-cooking pot.
But cultural associations of rice perhaps go one step further. Linguists Dmitrij Dobrovol'skij and Elisabeth Piiraninen have made a study of cross-cultural and cross-linguistic figurative language. They note that rice is further associated with the whole living situation, as exhibited in the phrase hiyameshi o kuwasareru, being made to eat cold rice, a way of expressing being treated coldly. Tanin no meshi o kuu, eating the rice of other people, means to gain experience and become mature by leaving one's family.
Unlike these rice expressions, a focus on undesirable or external sources of sustenance is not seen in common bread idioms. "Bread and water" may be understood to be the most minimal provisions, traditionally associated with provisions for prisoners, but the expression does not figuratively describe a chilly reception. There is no idiom related to eating bread somewhere else and to say it would simply suggest a sandwich obtained elsewhere, not a vital representation of becoming independent from Mom and Dad.
A traditional name for Japan is Toyoashihara no Mizuho no Kuni--the land where abundant rice shoots ripen beautifully. Emiko Onuki-Tierney is an anthropologist who has done extensive research on the Japanese attitude toward rice, including writing a book titled Rice as Self: Japanese Identities through Time. According to Onuki-Tierney, in one story in the Kojiki collection of myths about the origin of Japan, the goddess Amaterasu is the mother of a "grain soul" and Jimmu, the first emperor of Japan, is the son of one. Amaterasu gives Jimmu rice grains and tells him to transform the wilderness into a land of rice. Onuki-Tierney points out that unlike other creation myths in the world, Japan's mythology is not about the creation of the universe but about changing wilderness through rice cultivation. While other Asian countries obviously also have rice, Japan's own rice has been viewed as distinct. Westerners were not traditionally thought of as bread-eaters but rather meat-eaters, as opposed to rice-eating Japanese people, due to Buddhist prohibitions in Japan on the consumption of meat.
The shamoji rice spatula is a symbol of the Japanese housewife. While less prevalent than it used to be, it can still be seen in various depictions of smiling women wearing kappogi long-sleeved aprons and holding the shamoji aloft, at the ready to serve up some warm nourishment. This contrasts vividly with the traditional Western images of angry housewives brandishing rolling pins, not equipped to joyfully roll out some pastry to supply their family members with a delicious savory or sweet pie, but rather to whack a wayward husband over the head. Occasionally Japanese women are portrayed using a menbo rolling pin in a similar way, but such representations are far less frequent than those of cheerful shamoji holders.
In this way, perhaps warm rice eaten at home has a cultural resonance not easily supplanted. Yet, as always, the picture is not completely black and white. When I spent a year in Europe for research a little while ago I made rice every day, thanks to a rice cooker a colleague returning to Japan after her own sabbatical had kindly passed on to me. On the other hand, many Japanese women I met in Europe had by and large happily abandoned rice for bread in their daily lives, and they expressed surprise and amusement that my daughter and I persisted in eating rice at least once a day. If rice is a symbol of physical and spiritual sustenance perhaps it can be said that variety is the rice of life.