Teiyo Maru was a transport of the Imperial Japanese Navy, typed AP. The wartime card places her in the Bismarck Sea convoy.
That convoy met the Battle of the Bismarck Sea in March 1943. The battle is the combat entry recorded for her, and it is the action in which she was sunk.
The battle line dates her loss to 2 March 1943. A strike recorded for the next day, 3 March 1943, lists bombs as the blow that sent her down. The fate note draws those dates together and records that Allied aircraft sank her on 2–3 March 1943.
The strike leaves the attacking aircraft unknown. Credit for the sinking stays with Allied aircraft, and the card states that the loss is not credited to one plane.
Teiyo Maru’s service ended in that fight. The hull was sunk in the Battle of the Bismarck Sea, lost to aerial bombs during the action of 2–3 March 1943.