rice vermicelli originated in south-eastern China, this pasta is an integral part of many Asian cuisines and can be found from India, through Southeast Asia, and on to China and Japan. It is probably most commonly associated with Cantonese cuisine, however, and its name in Cantonese, mifen, has made its way to Brazil, where the noodle is most commonly known as bifum. It is also occasionally marketed under this same name in English-speaking countries, though the package will likely also refer to the contents as rice vermicelli.
As Brazil doesn't have a tradition of Chinese immigration, bifum came to this country by way of Japan. In the early 20th century large numbers of emigrants left Japan to find their fortune in the coffee and orange plantations of São Paulo state, and today the city of São Paulo has the largest ethnically Japanese community in the world outside Japan.
Brazilians have taken enthusiastically to Japanese food, and even many small towns in Brazil have a sushi restaurant, probably the only non-Brazilian restaurant in town. Bifum noodles have found a place in Brazilian domestic kitchens as well,something that sushi hasn't accomplished - as elsewhere sushi is considered restaurant food in Brazil.
Preparing bifum for cooking is simplicity itself. The noodles do not have to be cooked. They only need to be soaked in hot water for about 10 minutes, and then they are ready to be stir-fried or tossed with a dressing and some chopped meats or vegetables in a salad.
One note of caution: there is another type of Asian noodle that is similar in size, shape and packaging that is made with mung bean flour, not with rice. In English, it is called bean-thread or cellophane noodles. This noodle is also known in Brazil, though really only in areas with a Japanese population. It is similar to bifum, but not close enough that it can be substituted for bifum in recipes.