SEOUL—North Korean women often risk their lives to defect to the South, crossing the heavily guarded Chinese border on foot before beginning a lengthy resettlement process. Then comes the loneliness.

When Na Soo-yeon arrived in Seoul in 2008 after fleeing North Korea, she found herself alone in an unfamiliar society where she knew no one. To ease her solitude, she sought a husband from South Korea who could provide companionship and help her adjust to life in the South.

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