From the article in question:

Notable exclusions

The bill notably excludes the possession of explicit anime or manga, a point of contention for campaigners who say that cartoons depicting child sexual abuse should also be banned.

Representatives of those industries say that while they support the ban on real child pornography, any move to censor their products would be an unjustified restriction of freedom of expression.

Daisuke Okeda, a lawyer and inspector for the Japan Animation Creators Association, said it was “natural that animation is exempted.”

“The goal of the law itself is to protect children from crime,” he said. “Banning such expression in animation under this law would not satisfy the goal of the law.”