How many movies have Hiroshi Koizumi and Koji Hashimoto collaborated on?

They have worked on 4 movies together! Their first movie together was Ghidorah, the Three-Headed Monster (1964) while their highest rated movie together was The Return of Godzilla (1984). They have not worked together since Godzilla 1985 (1985). They are most known for their science fiction films together.