Ghidorah, the Three-Headed Monster (1964)
Detective Shindo is assigned to protect the princess of a small kingdom, Maas Doulina Salno. Before she arrives in Japan, Princess Salno is seemingly assassinated as a mysterious meteorite lands in Kurobe Valley. As Mothra's fairies tour Japan, a scientific expedition examines the meteorite. Soon the princess, under the guise of a prophetess, appears to warn of great calamity with the reemergence of Godzilla, Rodan, and the arrival of a powerful space monster known as King Ghidorah. Mothra must now convince Godzilla and Rodan to set aside their hatred of humanity or face the space monster alone.