Aiyo Maru was a transport of the Imperial Japanese Navy, typed AP, and like other ships that carried the maru suffix she spent her recorded wartime service moving men and cargo rather than fighting as a combatant in her own right.
The only operation set down for her is the Battle of the Bismarck Sea. In that action she sailed as a transport in the Bismarck Sea convoy, the formation Allied aircraft struck in the opening days of March 1943.
The battle line for 2 March 1943 records her as sunk. The fate of the hull is given across 2–3 March 1943: she went down under attack by Allied aircraft during the Battle of the Bismarck Sea.
A strike dated 3 March 1943 names bombs as the weapon that finished her. The attacker is left unidentified. The sinking is credited to Allied aircraft as a body of attackers, and it is not assigned to any one plane.
That is the whole of her recorded end. Aiyo Maru was lost in the Bismarck Sea convoy fight, bombed and sunk by Allied aircraft over those two days in March 1943, with no single aircraft named as the one that sent her down.