The Japanese fleet was en route to Guimares Island in the central Philippines on 13 June, where they intended to practice carrier operations in an area better protected from submarines, when Vice Admiral Jisaburō Ozawa learned of the American attack on the Mariana Islands the previous day.
Upon reaching Guimares, the fleet refuelled and sortied into the Philippine Sea, where they spotted Task Force 58 on 18 June.
The Americans failed to locate Ozawa's ships that day and the Japanese turned south to maintain a constant distance between them and the American carriers as Ozawa had decided on launching his air strikes early the following morning.
At this time, the 652nd Naval Air Group consisted of 81 Zeros, 27 D3As, 9 Yokosuka D4Y "Judy" dive bombers and 18 Nakajima B6N "Jill" torpedo bombers, roughly evenly divided among the three ships.
The three carriers began launching their first air strike of 26 bomb-carrying A6M2 Zeros, 16 A6M5 Zeros to escort the other aircraft and 7 B6Ns at about 09:30.
Most of these aircraft were misdirected and failed to find any American ships, although a dozen persisted in their search and found one of the American task groups.
A B6N, 5 bomb-carrying Zeros and an escorting Zero were shot down by the defending fighters and no damage was inflicted on any American ships.

A second air strike of 27 D3As, 9 D4Ys, 2 B6Ns and 26 escorting Zeros was launched around 11:00, accompanied by at least 18 A6Ms and B6Ns from Shōkaku and Zuikaku.
They had also been given an erroneous spot report and could not find any American ships.
The 652nd aircraft headed for airfield at Rota and Guam to refuel while those from the other two carriers returned to them.
A pair of Zeros and 6 D4Ys bound for Rota spotted the carriers Wasp and Bunker Hill en route, but failed to inflict any damage on the American ships while losing 5 D4Ys to anti-aircraft fire.
Radar had spotted those aircraft headed for Guam and they were intercepted by 41 Grumman F6F Hellcats.
Only a single A6M5, 1 D4Y and 7 D3As of the 49 Japanese aircraft survived the encounter and landed.

At dusk, the Japanese turned away to the northwest to regroup and to refuel and the Americans turned west to close the distance.
They discovered the retiring Japanese fleet during the afternoon of the following day and Vice Admiral Marc Mitscher ordered an air strike launched.
They found the ships of the Second Carrier Division and hit Jun'yō with two bombs near her island.
The ship was not badly damaged, but flight operations had to be suspended.
The 652nd Naval Air Group claimed seven American aircraft shot down and four more probably shot down, but lost eleven Zeros, plus another three that had to ditch.
The air group was disbanded on 10 July with many of its remaining personnel being assigned to Air Group 653.

After repairs at Kure, Jun'yō remained in the Inland Sea without aircraft until 27 October, when she was tasked to transport material to Borneo.
On 3 November, she was attacked by the submarine Pintado near Makung, but her escorting destroyer, Akikaze, deliberately intercepted the torpedoes and sank with no survivors.
On her return voyage, the ship was unsuccessfully attacked by the submarines Barb and Jallao.
On 25 November, she sailed for Manila via Makung to rendezvous with the battleship Haruna and the destroyers Suzutsuki, Fuyutsuki, and Maki.
Having loaded 200 survivors of the battleship Musashi, Jun'yō was attacked by the submarines Sea Devil, Plaice and Redfish early in the morning of 9 December 1944.
She was hit by three torpedoes that flooded several compartments and killed 19 men.
These gave her a 10°–12° list to starboard, but she was able to proceed on one engine.
She reached Sasebo the following day and began repairs on 18 December.

The repairs were abandoned in March 1945 for lack of materials and the ship was moved from the dock to Ebisu Bay, Sasebo, on 1 April.
Efforts to camouflage the ship began on 23 April and she was reclassified as a guard ship on 20 June.
Jun'yō's armament was ordered removed on 5 August and the ship was surrendered to the A
The Japanese fleet was en route to Guimares Island in the central Philippines on 13 June, where they intended to practice carrier operations in an area better protected from submarines, when Vice Admiral Jisaburō Ozawa learned of the American attack on the Mariana Islands the previous day. Upon reaching Guimares, the fleet refuelled and sortied into the Philippine Sea, where they spotted Task Force 58 on 18 June. The Americans failed to locate Ozawa's ships that day and the Japanese turned south to maintain a constant distance between them and the American carriers as Ozawa had decided on launching his air strikes early the following morning. At this time, the 652nd Naval Air Group consisted of 81 Zeros, 27 D3As, 9 Yokosuka D4Y "Judy" dive bombers and 18 Nakajima B6N "Jill" torpedo bombers, roughly evenly divided among the three ships. The three carriers began launching their first air strike of 26 bomb-carrying A6M2 Zeros, 16 A6M5 Zeros to escort the other aircraft and 7 B6Ns at about 09:30. Most of these aircraft were misdirected and failed to find any American ships, although a dozen persisted in their search and found one of the American task groups. A B6N, 5 bomb-carrying Zeros and an escorting Zero were shot down by the defending fighters and no damage was inflicted on any American ships.
A second air strike of 27 D3As, 9 D4Ys, 2 B6Ns and 26 escorting Zeros was launched around 11:00, accompanied by at least 18 A6Ms and B6Ns from Shōkaku and Zuikaku. They had also been given an erroneous spot report and could not find any American ships. The 652nd aircraft headed for airfield at Rota and Guam to refuel while those from the other two carriers returned to them. A pair of Zeros and 6 D4Ys bound for Rota spotted the carriers Wasp and Bunker Hill en route, but failed to inflict any damage on the American ships while losing 5 D4Ys to anti-aircraft fire. Radar had spotted those aircraft headed for Guam and they were intercepted by 41 Grumman F6F Hellcats. Only a single A6M5, 1 D4Y and 7 D3As of the 49 Japanese aircraft survived the encounter and landed.
At dusk, the Japanese turned away to the northwest to regroup and to refuel and the Americans turned west to close the distance. They discovered the retiring Japanese fleet during the afternoon of the following day and Vice Admiral Marc Mitscher ordered an air strike launched. They found the ships of the Second Carrier Division and hit Jun'yō with two bombs near her island. The ship was not badly damaged, but flight operations had to be suspended. The 652nd Naval Air Group claimed seven American aircraft shot down and four more probably shot down, but lost eleven Zeros, plus another three that had to ditch. The air group was disbanded on 10 July with many of its remaining personnel being assigned to Air Group 653.
After repairs at Kure, Jun'yō remained in the Inland Sea without aircraft until 27 October, when she was tasked to transport material to Borneo. On 3 November, she was attacked by the submarine Pintado near Makung, but her escorting destroyer, Akikaze, deliberately intercepted the torpedoes and sank with no survivors. On her return voyage, the ship was unsuccessfully attacked by the submarines Barb and Jallao. On 25 November, she sailed for Manila via Makung to rendezvous with the battleship Haruna and the destroyers Suzutsuki, Fuyutsuki, and Maki. Having loaded 200 survivors of the battleship Musashi, Jun'yō was attacked by the submarines Sea Devil, Plaice and Redfish early in the morning of 9 December 1944. She was hit by three torpedoes that flooded several compartments and killed 19 men. These gave her a 10°–12° list to starboard, but she was able to proceed on one engine. She reached Sasebo the following day and began repairs on 18 December.
The repairs were abandoned in March 1945 for lack of materials and the ship was moved from the dock to Ebisu Bay, Sasebo, on 1 April. Efforts to camouflage the ship began on 23 April and she was reclassified as a guard ship on 20 June. Jun'yō's armament was ordered removed on 5 August and the ship was surrendered to the A
Japanese aircraft carrier Jun'yō