Where better to learn a martial art than Japan. In addition to the Japanese martial arts, there are also classes available in many other non-Japanese martial art disciplines. Since there are so many dojo in Japan I have specifically chosen ones that have an English webpage and welcome foreigners.

You can also find local dojos in your area by visiting your ward office and seeing whether they have a list of contacts. Finally, some gyms also have martial arts classes for children. You will need to check with the gym directly.