How many movies have Masato Katō and Seiichi Takayanagi collaborated on?

They have worked on 3 movies together! Their first movie together was Molester Diary: A Man Who Kept Stroking Ass 4 (1996) and was their highest rated movie together. They have not worked together since 尻を撫でまわしつづけた男 痴漢日記6 (1998).