Eating out like a boss
Quicky: although it’s strictly not done to stick your chop sticks into your food and leave them there (or so I read somewhere), I have learned that it is in fact OK to spear your riceball (or to stab it in the chest, as I’ve heard it is called) so you can simply eat it off your sticks.
Tip: stick your chop sticks in, not too close to each another.
Another tip: you put your used sticks (for grilled items) in here:
Also: it is not considered impolite to eat your sushi using your fingers, instead of using chop sticks.
Bonus: generally, you never tip in Japan. (or so I read)