Tokyo - At first, they blackmailed their victim. Again and again, four high school students sent text messages to their classmate, demanding hundreds of thousands of yen.
Then they posted a nude photograph of the 18-year-old boy online, complete with phone number and email, leading to more text messages on his mobile phone and humiliation.
In the end, the student saw only one solution to end his torment - and jumped to his death from the roof of his school in Kobe, central Japan, in late 2007, a case that shocked the Japanese public.