Youth is at a premium in Japan. Video game characters are often in their teens (or younger). And in candy-coated world of idols, girls start young. But decade after decade, there's been one pin-up who keeps on keeping on: 45-year-old Natsuki Okamoto. And there's a reason for that. She puts out. » 8/16/11 2:00am 8/16/11 2:00am