Namasu is the dish made by thinly cutting (or slicing) sea foods, vegetables or fruits and dressing them with seasoning materials based mainly on vinegar. It is also eaten as a lucky charm in the New Year. Namasu in Japan emerged and developed in its own right. なます, namasu' in old Japan meant this 'namasu, 膾,' but after "Insei" period (period of the government by a retired emperor) it was identified with 'aemono' which is the dish made by chopping sea foods or vegetables, dressing them with flavoring materials. And later, something resembling 'shojin namasu' (dish of only vegetables seasoned in vinegar) appeared. At present, the seasoning materials used for 'namasu' are sweet vinegar, "nihaizu" (vinegar and soy sauce mixed in roughly equal proportions), "sanbaizu" (vinegar, soy sauce and mirin (or sugar) mixed in roughly equal proportions), Japanese citron vinegar, "tadesu" (vinegar with water pepper) and so on, but traditionally boiled-down sake (made by mixing dried bonito, Japanese apricot, sake, water and soy sauce and boiling them down) and so on were also used.
As osechi food (special food for New Years in Japan), "kohaku-namasu" is often used, which is made by slicing "daikon" (Japanese radish) and carrot, marinating them with sweet vinegar and seasoning them with a flavor of Japanese lemon peel. Here, daikon and carrot are regarded as red and white "mizuhiki" (an ancient applied art of tying various knots of special cords) which is said to be a good omen. The red and white are regarded as the flags of Genji and Heike and also called "genpei-namasu."
"Nuta" which is the dish made by seasoning sea foods or vegetables with vinegared miso is also a kind of namasu.
How to make the kohaku-namasu
Shred daikon and carrot in five centimeters long. Before shredding them, you can peel them.
Salt the shredded daikon and carrot and when they are tender, wring them dry. On this occasion, you can pickle daikon and carrot separately or pickle by pressing them under a heavy stone.
Mix them with vinegar and sugar (alternatively you can use salt and water) and pickle them with red peppers.
(Firstly, pickle half of them, wring them dry and if desired you can pickle them again.)
Shred Japanese lemon peel and mix them.
Proverbs and common expressions
Namasu' in proverbs and common expressions often means the dishes which used the fillets of raw meat and raw fish in ancient China.
Atsumono ni korite namasu wo fuku'
After burning the tongue or mouth by eating a hot "atsumono" (soup or soup dish), they eat even a cold namasu by blowing on it. This means that once failed and disgusted, they become uselessly careful ('Atsumono ni koritarumono, ae wo fuku' (Those who were disgusted with a hot soup blow a marinated food or sashimi) means the same). "Ae" means an aemono or sashimi.
Jinko ni kaisha suru' (kaisha (膾炙), namasu and broiled meat are eaten by many people)
As many people like to eat '膾と炙' (namasu and "aburi" (broiled meat)), this meant it spread and became popular among many people.
Namasu ni tataku' (Beat namasu)
As namasu is shredded, this figuratively means that a man is beaten violently by many people.
Origin and so on
膾 ('kai' in a Chinese reading)' originally referred to the dish which was made by cutting the raw animal meat out and mixing it with seasonings.
The dishes which were cooked similarly by using a fish meat were called 'namasu (鱠, 魚膾).'
The word origin of 'namasu' in Japanese is unknown, but some say that 'namashishi' (raw meat) or 'namasuki' (raw cut) are the origin. Generally speaking, namasu is interpreted as '生酢, namasu' (raw vinegar), but as mentioned before, originally vinegar was not always used as a seasoning and so some say that it is a sort of folk etymology.
In Korean Peninsula, '膾 or 鱠, namasu' is called 'fue.'
Fue includes the dishes like sashimi. For example, 'yukke' (raw meat food) is spelled as '肉膾' (meat namasu) and is regarded as a kind of namasu. Also, the materials are not always raw fish or raw meat and some fues are made by heating the innards of farm animals and mixing them with vegetables.