Soba and udon noodle bars
Tokyo has many soba and udon noodle snack bars and we eat them at bars standing up.
They are sold at from 3 to 6 USD and the bars feature some kinds of toppings, including kelp, tempura, eggs, sliced polk and so on.
The vending machine are put at the entrance. We buy tickets in the machine and pass it to clerks.
The bars are rather reasonable and convenient.