Just to add some context: I was with a Japanese friend at a うどん and そば restaurant in 浅草 where they had a small sign by the counter to buy their fresh noodles. However, the size of the portion was not indicated by a weight in grams or anything like that, it was a kanji/counter/symbol that looked like a checkbox... Something like this :
If I remember well, he told me it was an old kanji that denotes a well-defined quantity of noodles, a bit like 一斤{いっきん} is used for a loaf of bread.
However, I have tried hand drawn kanji recognition without success, gone through a few counter and unit lists but none of them seem to mention it.
So is this thing a kanji ? How is it pronounced ?
Thanks a lot !