Tokyo's metropolitan government has restricted the sale of traditional comics and cartoons which feature illustrations of sex crimes.

Manga comics often show child and other hardcore pornography with extreme depictions of rape, incest and other sex crimes.

They are regularly read in public places, such as trains and cafes.

Now Tokyo's governor, Shintaro Ishihara, has pushed through a bill which says people under the age of 18 must not be able to buy or rent materials that depict such sexual acts in "unjustifiably glorified or exaggerated ways".

A group of 10 major comic publishers has condemned the move as censorship and is vowing to boycott a major industry fair in Tokyo.