In June 1944, "Myōkō" participated in the Battle of the Philippine Sea. The Japanese fleet sailed from its anchorage at Tawi Tawi in response to the American invasion of the Marianas Islands. The Japanese high command was aware that American heavy bombers, based in the Marianas, could reach factories and shipyards in the Japanese home islands. This battle was later called the "Great Marianas Turkey Shoot" by American sailors, because over 300 Japanese carrier aircraft were shot down in a single day on 19 June.