Shigematsu joined the Imperial Army, where he served in a non-combat role at the Taiwan headquarters: "It was the most natural thing in the world for a young man like me, with his country at war, to join the army and serve the emperor."
十七歲時，竹永茂松被錄取日軍台灣軍司令部的軍屬，他坦言：「做為軍國少年為天皇陛下出征是理所當然的事。」