Remember when you would step out to the スーパー (sūpā, supermarket) just to pick up some 卵 (tamago, eggs), 牛乳 (gyūnyū, milk) or 砂糖 (satō, sugar)? Well, these days you're just as likely to pick up スーパーフード (sūpāfūdo, superfoods) from the スーパー as you are your daily necessities.

The shopping lists of health-conscious consumers are likely to include products such as ココナッツオイル (kokonattsu oiru, coconut oil), チアシード (chia shīdo, chia seeds) and アサイー (asaī, acai), but health-conscious Japanese are likely to stick with one staple that has done them well for centuries: 納豆 (nattō, fermented soybeans).

One of the country's most notable 健康食品 (kenkō shokuhin, health food products), 納豆 is made from 大豆 (daizu, soybeans) fermented with 枯草菌 (kosōkin, bacillus subtilis), a bacteria widely recognized as a probiotic. It's known to have its roots in the area of Mito, Ibaraki Prefecture, a region famous for わら納豆 (wara nattō), which is 納豆 wrapped in rice husks.