[Zerdame]

No, if you enter on a tourist visa, all you need is your passport and your air ticket to arrive in Japan with. Depending on where you're from but most countries have a tourist visa waiver with Japan so you get a fixed number of days in the country upon arrival. Although they don't check how much you bring into the country if you're just the average travelling joe, I would tell you to bring a sufficient amount that you're comfortable with. Japan isn't the cheapest country after all and if you're going to be scrimping on everything, it might be that much of a fun trip.