'Little idols': Japan's dark obsession with young girls

In a cramped and dark venue in a sleazy Tokyo district, dozens of middle-aged men cheer at a performer on stage: The object of their adoration is a six-year-old girl. She is a so-called "idol" singer -- common in Japan, where rights groups have complained that society's sometimes permissive view of the sexualisation of young girls puts minors at risk.