OSAKA — It's a Saturday evening in early 2006, and four Osaka-area 15-year-old friends, Kenji, Taro, Yoko and Yuka, show up at a theater to see the latest movie. The time is 6:45 p.m., 15 minutes before the movie starts.

The woman in the ticket booth asks to see some identification.

"Sorry, you're all 15 years old and this movie starts at 7 p.m. We can't let you in," she says.