盤根錯節 [ㄆㄢˊ ㄍㄣ ㄘㄨㄛˋ ㄐㄧㄝˊ; pan2 gen1 cuo4 jie2]
  twisted roots and intertwined joints (idiom); complicated and very tricky
  knotty and deeply-rooted difficulties
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  盤根錯節
  ばんこんさくせつ
  noun (common) (futsuumeishi)
  hard to penetrate event or situation
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