A family photo from 1953 shows Yoon Heung-gyu with Kim Young-sook, whom he later married, in Gwangneung Forest outside Seoul. Yoon served in South Korea’s military after he left the North. He will travel to North Korea this week to see his younger sister. “I wasn’t expecting it to happen,” he says.

A family photo from 1953 shows Yoon Heung-gyu with Kim Young-sook, whom he later married, in Gwangneung Forest outside Seoul. Yoon served in South Korea’s military after he left the North. He will travel to North Korea this week to see his younger sister. “I wasn’t expecting it to happen,” he says.