What are community associations (jichi-kai/chonai-kai)?
In Japan, there are organizations in each district that are generally referred to as chonai-kai or jichi-kai.  The chonai-kai or jichi-kai organize or supervise the kairanban (a file containing notices from public offices or the community attached to a clipboard, etc), and also organize festivals and disaster prevention activities.
Membership fees collected from each resident cover expenses incurred in running these activities.  If they are residents of the community, foreigners can also become members of the community organization.  Please listen the next time an organization committee member visits you to talk about joining such an organization.

Note 1 The information given is that confirmed as of July 2002. Note that a new system or system revisions may have been introduced after this date.

This information is from the CLAIR website. The Council of Local Authorities for International Relations (CLAIR) was established in July 1988 in response to rising concerns about local level internationalization in Japan.