Non-commissioned officer's pilot badge.
Engraved
八十四期 - 84th Class
多田 - Tada
Original case.
下士官操縦徽章 - Non-commissioned officer's pilot badge
Akiba Medals ink stamp https://asiamedals.info/threads/badges-and-watch-fobs-made-by-akiba-medals-tokyo-akiba.21820/