One of the universal laws of the planet is that when you have finished your enjoyable dinner at your favourite restaurant, you summon the check by signing your hand with an imaginary pen, letting the waiter know you would like to pay. That is, it's a universal law everywhere except in Japan. Signing your hand in the air is more likely to illicit a pen from the waiter or a simple confused look of "what is that person doing waving his hand in the air?".
I've always wondered why this is but when you consider that signatures aren't used in Japan it becomes obvious. People don't understand because Japan doesn't use signatures. It uses hankos. So to summon the check you cross your index fingers and soon you will be on your way. Simple really. And this gives me a good excuse to show a picture of a restaurant. Not just any but one of my favorite in Japan. The Hacienda in Daikanyama. Order the frozen margarita and ask for the "yarda" version. Trust me. It'll make you happy.