Weather at the moment
Weather all year round
Tokyo has a humid subtropical climate. The city enjoys relatively mild winters, with little or no snow (5/6°C in January and February). But summers are hot (often over 32°C) and especially very humid. Spring and autumn combine the best weather conditions with pleasant temperatures and are the tourist high season. The rest of the year corresponds globally to the low tourist season.
The currency is the yen, the exchange rate is easy, and we pay more often in cash. Credit cards are not always accepted. Most of the budget will be spent on accommodation, which is quite expensive, especially in Tokyo. But you can eat for a very decent price and transport is no more expensive than in France, especially if you are thinking of taking a Japan Rail Pass. Never tip Japan, it's a kind of insult!
For Tokyo, no visa is required for a stay of 90 days or less. All you need is a valid passport for the duration of your stay, a return flight ticket and enough money to support yourself on site in case of an inspection. When passing through customs, foreigners over 16 years of age will be photographed and will have to leave their fingerprints digitized.
In Tokyo, pollution and summer heat are to be taken into account for vulnerable people. There is no malaria in Japan, and no vaccine is required to enter the country. Vaccines against tetanus, diphtheria, polio (unless up-to-date) and hepatitis A (unless immunized) are recommended in Japan. Tokyo has a remarkable hospital structure (but it is necessary to check before departure that the insurance will cover medical expenses, which are high in this country). Embassies have their own doctors attached.