just to complete the existing answer:for the Immigration form:you need to put an address + phone number: if you stay in several places, just put the one of the first hotel/place you intend to stay in. They do not check anyway.For the customs form:Assuming you are not a criminal, you are not importing drugs/ weapons, etc so it is better to answer the related questions with no… there is also a question about have you ever been charge with a felony in Japan or something like that.In the new forms, you don’t have to declare how much cash you are bringing in Japan unless it’s over a large amount (for us, 10000 euro.). Same for whatever you are bringing if it is not above some given quantities/amounts.