What is Noren?

暖簾 のれん Noren

Noren are curtains with vertical slits hung in front of restaurants, bars, and shops during business hours. The name of the shop or a symbol indicating the products sold there may be dyed into the cloth, so the noren also functions as a shop sign. Since a shop’s noren symbolizes the shop, the term has also come to refer to a business’s goodwill. Allowing an employee to set up a shop with the same name is called noren-wake (sharing the noren).

There are other popular phrases using "noren."

Noren ni udeoshi "のれんに腕押し" means doing something useless or it's a waste of effort.
In English, you can say, "it is like beating the air (wind)."

Noren ni kakawaru "のれんにかかわる" means "affect the credit (good name) of the store (our business)" or "affect our good reputation"

Noren ni kidugatuku "のれんに傷がつく" means "lose credit" or "lose face"

Noren wo orosu "のれんを下ろす" means "close the store" or "close our business"