As described in the chapter on the Val, Joichi Tomonaga had led the attack on Midway that morning, during which his Kate’s left fuel tank was damaged. He managed to return to his carrier Hiryū. Shortly after, the ship survived the devastating Dauntless attacks that set the Akagi, Kaga and Sōryū ablaze — Hiryū had manoeuvred clear and remained the only operational Japanese carrier. She immediately launched a strike of 18 Vals and 6 Zeros against USS Yorktown, which had been located by a reconnaissance plane from the cruiser Chikuma. The attack was met with fierce resistance — thirteen Vals and three Zeros were shot down — but they still managed to score several hits on the Yorktown.
Soon after, one of Sōryū’s Judys returned with the startling news that there were in fact three American carriers in the vicinity. A new strike force was quickly assembled under Tomonaga’s lead, consisting of 10 Kates and 6 Zeros. His left fuel tank was still perforated, and he was asked to switch to another aircraft. He refused, pointing out that every plane was needed. He simply ordered the ground crew to fill his right tank and took off, fully aware that he had fuel for a one-way trip only.
They were ordered to attack one of the two undamaged American carriers, targeting the Yorktown only if the others could not be found. Around 14:00 they sighted what appeared to be an undamaged carrier — it was in fact the Yorktown, which had been so swiftly repaired that Tomonaga mistook her for a fresh ship. At 14:32 he radioed his group: “Take position in preparation for attack formation,” and two minutes later: “Entire force attack!” On the way in two Wildcats shot down one Kate before being themselves brought down by the escorting Zeros. Closing in, the American CAP descended upon them and the AA fire intensified.
Tomonaga came in on the Yorktown from the aft port quarter, a Wildcat on his tail — possibly Jimmy Thach himself. Heavily damaged, he held his course and released his torpedo against the carrier. Immediately afterwards his left wing ruptured and he crashed into the sea. His torpedo missed its mark.
The Yorktown was nevertheless hit by two other torpedoes, one dropped by Lieutenant Toshio Hashimoto, leader of the second group of Kates. The hits crippled her so severely that she was later finished off by the Japanese submarine I-168. Hiryū did not escape either — that afternoon she was attacked by American dive bombers and eventually sunk, bringing the battle’s carrier exchange to a decisive conclusion.
