The Japanese schools and the vast majority of international schools (due in part to the fact that some of the larger schools like St. Mary’s and ASIJ are located well outside the city), offer a number of after school activities including access to computer labs, libraries, Boy/Cub Scouts of America, and a variety of competitive and intramural sports.
The Tokyo American Club (http://www.tac-club.org), the largest expat-friendly private membership club in Tokyo, caters to families with children of all ages. TAC, as it is often called, provides children with opportunities to participate in ballet, baseball, basketball, soccer, tennis, competitive swimming, and swim lessons, along with a number of martial arts programs (including aikido and karate), Boy and Cub Scouts, and a summer camp program. In January 2011 the Tokyo American Club will relocate to its previous location in Azabudai from its current temporary location. With the relocation, the club will be considerably larger and thus may begin to offer new after-school and weekend programs for children.
As Tokyo is notoriously known for not having much greenery, there are few parks within the city limits where children can comfortably play after school or on weekends. That said, three parks are worth mentioning, including Arisugawa Park (located just 3 minutes from Hiroo station), Yoyogi Park (one of the largest parks in the city with plenty of space for fun or relaxing, located next to Meiji Shrine and just 5-minutes away from Harajuku station), and Komazawa Park (http://www2u.biglobe.ne.jp/~inline/map/komazawa.htm).
For additional child-friendly activities and helpful resources, please refer to the title page, “Children”, of this section.