Hello!- from SIC
The national census is going to be carried out as of October 1st. This is done once 5 years and is the most basic statistical research for all residents in Japan. Everyone living in Japan, including foreign residents, is obliged to participate the census.
A census taker will visit each house to give out a survey questionnaire at the end of September. Please fill it in and submit.
You have 2 choices to turn in: ①Put it in the envelope and hand it to the census taker when a taker visits again ②Put it in the envelop (stamp is not required) and post it by October 7th (Thu.).
* The census taker has an ID.
Inquiry: National census in Ministry of Internal Affairs and Communications
http://www.stat.go.jp/data/kokusei/2010/special/English/index.htm/

~This is based on the SIC mobile phone email newsletter.