The estimated total cost for 2 weeks in Japan is $5450 (£4530, ¥715,000) for 2 people. How much money should I bring to Japan for 2 weeks? A good rule of thumb is to have about 10,000 to 20,000 yen with you in cash at all times. For 2 weeks, 100,000 yen (£650, $780) was plenty cash for us.