At Tokyo Game Show, they're taking mature games seriously. First indication: At Sony Computer Entertainment Japan's exhibitor area this year, all mature titles -- rated Cero, the Japanese equivalent of our "M" rating -- are being shown "behind closed doors."

To simply get in to the area to see these titles, I had to show my passport to verify my age; 17 and up only, folks. Once behind the curtain, I was asked to choose which of six games I wanted to see -- Resident Evil 5, Demon's Souls, SOCOM: Confrontation, Resistance 2, Killzone 2, and Yakuza 3. Once I did, I received a card and was then ushered to another line. After about 10 minutes of waiting, I was allowed access to a curtained off area to play my game of choice. (If you want to play another, you had to repeat the entire process.)

The whole of the Tokyo Game show floor is loud and overwhelming, and Sony's area is no exception. But behind the "17 and over" curtain is dark, scary ... frighteningly quiet. In short, it's incredibly mature.

I'm not entirely sure if all of the mature titles on the floor will require the same sort of age-verification, but I certainly don't remember seeing anything like this last year for any title. (Although I do recall the bloody Ninja Gaiden II being hidden inside a dark booth.)

We'll be trawling the Tokyo Game Show floor over the next few days to bring you the goods; check back for jet-lagged hands-on info, screens, video and more.