The Daily NK did a series of articles on the General Association of Korean Residents in Japan (Chongryon or Chosen Soren). Below are links to all seven parts:
Part 1: Chongryon feels the pinch
Part 2: Debts, Mergers, Collapses and Foreclosures
Part 3: Homecoming Project Speeds Chongryon Demise
Part 4: South Korea Visits Weakened Chongryon
Part 5: Chongryon Remittances and Investments
Part 6: “Study Group,” the Core of Chongryon
Part 7: Study Group Money Laundering Machine