Shop curtains adorn the entranceways of Japanese restaurants. They usually have the shop’s symbol or crest printed on them as an advertisements.
They are hung outside when the shop is open
and taken down when it is closed.
If you are interested in Sushi culture, I recommend SUSHIDO with sushi (We also have vegetarian menu) when you visit to Tokyo.
If you are interested in Shitamachi(Do you know Shitamachi?) ,secret spots in Tokyo and Japanese casual conversation for trip, I recommend Online class.