Hiroshi Tamura is keenly aware of the great changes that have taken place in his neighborhood in Sumida Ward, Tokyo, where he has lived for more than half a century.

Tamura, not his real name, is one of 850,000 people across the country who have been mobilized for the Oct. 1 national census.

As of the end of last week, he was able to meet only about 80 percent of the residents of the roughly 50 houses and apartment buildings he's assigned to survey.