Japan Good Conduct
Corporation
(社団法人) 日本善行会
This is a group mainly concerned with supporting volunteer activities. Affiliated
with the government Cabinet Office. It was established as a corporation on
June 10, 1949, but it seems to have existed in a different form from 1937 to
1948. So some of the badges and medals may be pre-war. However, if the
term '
Shadan Houjin [corporation]' appears on the piece, it would certainly be
post-1949.

The name of the group is
Shadan Houjin Nihon Zenkou-Kai, Japan Good
Conduct Corporation.

There seems to be three main medals, gold, silver, and bronze.

The official website is
HERE, but it is in Japanese.
Bronze medal.
Special Merit silver medal (pure silver).
Lapel pin.
Special Merit gold medal (pure silver).
Good Conduct gold medal (pure silver).
Bronze Badge.