The study in Pornography, Rape and Sex Crimes in Japan discovered that as Japan’s strict pornography laws were relaxed there was a corresponding drop in sex crimes against children and women.
The most dramatic decrease in sex crimes was seen when attention was focused on the number and age of rapists and victims among younger groups. We hypothesized that the increase in pornography, without age restriction and in comics, if it had any detrimental effect, would most negatively influence younger individuals. Just the opposite occurred. The number of juvenile offenders dramatically dropped in every period reviewed from 1,803 perpetrators in 1972 to a low of 264 in 1995; a drop of some 85%. The number of victims also decreased particularly among the females younger than 13. In 1972, 8.3% of the victims were younger than 13. In 1995 the percentage of victims younger than 13 years of age dropped to 4.0%, a reduction of crimes against minors of 50%.