Kyoto and Yokohama messengers are planning to have camping for few days near the CMWC spot. Don't worry,it is totaly legal. Wakasu park has official camping site. Here is the details.
date 9/19-9/23(4nights,5days) fee 6000yen($60)for 4 nights.(even if you stay only one night,it cost 6000yen also.) Where WAKASU park (tokyo prefecture park) Included tents,sleeping bags(recommended bring your own),blankets,lights,mats(number limitation),and breakfast.
probably 60 to 80 people will available. If you are interesting in this plan,contact me. It suppose to be announced by official CMWC site soon.