July 25, 1943 the Japanese submarine I-25 departed from Truk to conduct operations off the Solomons and Espiritu Santo. After sending the floatplane to fly over Espiritu Santo and sending a message with the results (on Aug. 24) the boat was never heard from again. Post war examination yielded no conclusive cause for the loss of the I-25 and her 101 man crew. An attack by USS Patterson DD-392 on Aug. 25 could have destroyed the boat, however this may have been an attack against RO-35. A mine or some operational defect could also have caused the loss.

I-25 under Commander Meiji Tagami accounted for the loss of four vessels, including the Soviet submarine L-16, however at the time of her loss she was under the command of Commander Masaru Kohiga, who apparently recorded no combat victories during his career.