This is sort of a trick question – at all but the most upmarket or westernised restaurants in Japan, you won’t have to ask for the bill, because it will be kept on your table and updated by the waiting staff as your meal progresses, and you then take it to the cashier counter as you leave to pay, rather than paying at your table.
\nOr if you’re in a conveyor belt sushi place, they’ll simply count up the number of used plates, each plate’s cost being determined by it’s colour or pattern, according to a key you will usually see on the wall.
Perhaps that’s why most phrasebooks and dictionaries don’t include this seemingly essential phrase.
But if you do find yourself needing to ask for the bill, it’s really easy. Just say “Kanjoo o kudasai“. Kanjoo (that double o is just a long ohhh sound rather than an oh-oh) means bill (cheque if you’re American) and ‘o kudasai‘ means “please give me”. Altogether that’s “please give me the bill” or “please can I have the cheque“.
See our Japanese for travellers guide for more tips (coming soon).