Badge with a similar design elements https://asiamedals.info/threads/1935-three-city-union-air-defense-maneuvers-commemorative-badge.24819/
1st variation in base metal.
Obverse
奮勵努力 - Making Strenuous Efforts; Exerting Oneself
第二分團 - 2nd Branch
reverse
昭和十一年七月盛夏 - July 1936, Midsummer...
1936unitedairdefensemaneuversbadgeairdefenseairdefensemaneuversbadges
japanese airdefensebadge
japanese badge
mark 純銀
nihonbashi ward air raid defense corps badge
日本橋區防護團第一分團連合防空演習参加章
防空演習参加章