Census Worker Badges
国勢調査章
Special census taker badge. Showa 14 [1939]
The 'special' here refers to the census, not the worker (I think).
Taisho 9 [1920]
Note the reverse shows that Korea, Taiwan, the Kuril Islands, and the southern half of Sakhalin were included in the Japanese Empire.
Showa 10 [1935]
Appreciation document for a man who was a census taker. Dated Showa 15 [1940].
FROM LEFT
TOP ROW: 1950, 1955, 1960
BOTTOM ROW: 1965, 1980, 1985
Taisho 14 [1925]
Undated Agricultural Census badge.
Showa 5 [1930]
An official document for authorization as a worker in National Census of 1930. This
was issued by the Prime Minister's office and has the imperial paulownia leaves
watermark. This document also has a 3-sen 1930 National Census postage stamp
affixed. This was not part of the document so it was probably added by the recipient
as a commemorative. Awarded to Miyano Sueyoshi on July 20, 1930.
An official document for appreciation for work in National Census of 1935. This was
issued by the Prime Minister's office. Awarded to Miyano Sueyoshi on December 20, 1935.
Agricultural census badge with original box. Unknown date, but the maker
name uses 'Dai Nippon' so it is pre-WW2.

Two national census worker badges.
One is dated Showa 40 [1965] and the other is 1950.
Showa 15 [1940]
Showa 45 [1970]
Official Census worker certificate from the office of the prime minister.
Dated Showa 10 [1935] July 20.
Awarded to a man named Sakiyama Fujitaro.
Showa 35 [1960]
The badges for the censuses were given to those who were official census takers (or somehow employed by
the census bureau). They may have conducted a door-to-door survey, but more likely the heads of the
communities gave over information to the census takers. I am not sure of the method.

The reverse phrase is
Naikaku (内閣), meaning it is an official government issued piece.

There was only one medal awarded for the census, and that was in 1920. See it HERE.
Showa 5 [1930] Miyazaki Prefecture Census Worker Badge
Heisei 7 [1995]