See also https://asiamedals.info/threads/1936-army-special-large-maneuvers-in-hokkaido-imperial-visit-security-guard-commemorative-badge.24163/
In the center
衛 - Security Guard /衛 - to guard; to protect; to defend/
昭和拾壹年陸軍特別大演習竝地方行幸 - 1936 Hokkaido Army Special Large Maneuvers in the...