The story begins when the police raided the offices of Chongryon, the association of Koreans living in Japan. It is a transparent secret that Chongryon is nothing but a front for North Korean spying in Japan, but this summer the new Japanese cabinet led by Shinzo Abe decided to clamp down on it.
This is what resulted :
ニコニコ動画(β) | 朝鮮総連映像部製作・これが総連神戸本部捜査の全貌だ ！ (AmebaVision)