Jisaburō Ozawa
The 1st Mobile 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 refueled 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 airstrikes early the following morning. He had deployed his forces in a "T"- shaped formation with the Third Carrier Division at the end of the stem, ahead of the First and Second Carrier Divisions that formed the crossbar of the "T". "Zuihō" and her consorts were intended to draw the attention of the Americans while the other carriers conducted their airstrikes without disruption.