Kappa sushi, a (cheap) chain of sushi restaurants.
The system is very simple, each different type of food has a different price which is reflected in different types of plates; you just grab the plate of whatever you see and want to eat, and afterwards the waiter/waitress will add everything up for your bill.
Each table includes a screen where you can order the pieces of sushi, or miso, or takoyaki, or dessert, or drinks that you want, which are brought to you by a “train”. You also have free water (as in EVERY restaurant in Japan) and free green tea.
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