Illegal arrests, forced expulsions, "kidnappings" by security police and beatings by hired thugs. No, it's not another dispatch from a violent banana republic. Those accusations come from the leafy back-streets of Ichigaya, Tokyo, home to a branch campus of the prestigious Hosei University.

Hosei authorities and a group of students are locked in a poisonous struggle that has turned the campus into something resembling a low-security prison.

Entrances are guarded by newly installed CCTV cameras and jittery guards equipped with Bluetooth headsets. Notices have been published at many sites naming and shaming "troublemakers" who have been expelled, and the police are on call in case things get out of hand.