Kōji Wakamatsu
In the early 1960s, several movie studios began producing "pink films". With censorship laws prohibiting genitals from being seen but otherwise free to express anything, these movies quickly diversified to fill all genres, including rape and bondage. Throughout the 1960s, the "pink films" were mainly produced by low-budget, independent filmmakers such as Kōji Wakamatsu. In 1971, the major studio Nikkatsu entered the pink film genre.