I'd like to introduce 4 websites for you. It probably helps you make choices that leads you to where you should go in Japan.
This website covers whole Tokyo area. It shows an area guide that makes you understand where the things are and happen. There is a calendar telling you about cultural events that you might enjoy. You can decide when and where you want to go to Tokyo.
As you know, Lonely Planet is the best guide book as your partner for travel. You can trust this website based on Lonely Planet when you go to Japan. Additionally you can find a flight and place to stay through this website. Here is everything you need when you go on a trip.
It has been a website for more than 20 years. It's easy to find a lot of information about Japan because local people let you know good places and events to go. It arranges information so properly that you can enjoy deciding your itinerary.
Time Out Tokyo
It focuses on Tokyo. This website is for people who just arrive at Tokyo and don't have any plans. It introduces the things timely. There is a topic "Things to do in Japan" separated by 4 section, Today, This week, This weekend and This month. Check this up when you are still thinking about what you're going to do although you are in Japan.
With these websites, you will enjoy your travel in Japan. Don't miss any amazing events! I hope you make the best trip!