Sing a Song of Sex (Japanese)

A group of provincial high school students, in Tokyo for their university entrance examinations, are thoroughly disillusioned with the older generation and see no hope for the future. They respond by going around singing dirty songs. A Korean prostitute teaches them that these songs are not only funny - they can be sad as well. Their fantasies have been centering around a rich girl they have seen. Now, still in fantasy, they set about raping her.