(The inverse is also true: Japan is rather lax about CSAM possession, about to the same degree as America is lax about weed possession. It's technically a crime but most people caught will be let off with a fine and a warning.)
http://fileserver.idpc.net/library/The-history-current-state...
Quite the opposite, in fact. CSAM is a pillar of the manga industry. Enjo kosai (compensated dating) is a cultural norm.