They started performing on stages in Tokyo's Akihabara electronics district, and today their ubiquity is unrivaled. The current flavors of the month pepper the TV schedules and covers of weekly magazines all year round. In Tokyo, you can't swing a carrot without hitting a giant poster of one or a bunch of the all-grinning, all-dancing "Vegetable Sisters." AKB48 are, hands down, the busiest and most successful girl group in Japan.

They have spawned spinoffs in other cities: SKE48 from Nagoya's Sakae district, NMB48 from Osaka's Namba neighborhood and HKT48, from Fukuoka's Hakata. Last year, their inspiration transcended national borders and a testy territorial dispute as the franchise set up shop in Shanghai as SNH48, hot on the heels of the group's first foreign foray, Jakarta's JKT48. Another offshoot, TPE48, is planned for Taipei.

The original AKB48 troupe now numbers 87 members (that's including "trainees"), making it the largest pop group in the world. Among these teenagers and 20-somethings, cut-throat competition has arisen alongside gross disparities between the fortunes of the most popular, the less so, and those whose day on the big stage just never comes.