You have water-proofed yourself with a fancy umbrella, some nice Wellingtons and maybe even a raincoat and now you want to fight laziness and get out to enjoy the day. Here are some tips on where to go an what to do when it is the rainy season or just another rainy day of the year.
You can enjoy some amazing flower viewing. The ajisai (紫陽花) or hydrangea flowers in English, are blooming during this wet season and you can enjoy them best in Kamakura, south of Tokyo. The flowers are usually associated with the rainy season and their color gets more intense with rain. It takes just a little more than an hour from Shinjuku station to reach the beautiful old town of Kamakura. There is a lot of sightseeing to do and you can easily spend a whole day there. Do not forget to visit the Great Buddha, since that is one of the most famous attractions there.
There is nothing better than going to a real outdoor onsen (温泉), sitting outside, relaxing and not doing anything but listening to the calming pattering sound of the rain. If you have never been to any, this is the perfect time to try one out!
Visit a large or a small temple, it does not matter. You will definitely experience a magical atmosphere during a rainy day, especially if it is misty.
If you are just not an active person or can not get the right attitude to enjoy a rainy day outside, you can always switch to an indoor activity. Find out what galleries are showing currently, visit a museum with an interesting exhibition, go to see a film in the cinema (choose a Japanese one to improve your language skills) or just do plain shopping.