See also https://asiamedals.info/threads/tokyo-nichi-nichi-shimbun-sen-man-shi-tourist-group-badge.23869/
Obverse
満州國視察大毎旅行會 - Manchukuo Sightseeing Osaka Mainichi Shimbun Travel Association
In the center emblem of Mainichi Shimbun newspaper https://en.wikipedia.org/wiki/Mainichi_Shimbun
