Pope Francis' trip to Japan this weekend might fulfill a wish he gave up on decades ago as a young man in South America.

The 82-year-old pontiff is set to start a four-day tour Saturday, visiting Nagasaki and Hiroshima on Sunday, followed by Mass at Tokyo Dome on Monday. He will be the first pontiff to visit in 38 years, following St. John Paul II in 1981.

Jorge Bergoglio, now Pope Francis, was 21 when he contracted pneumonia. He was in critical condition for three days, barely surviving surgery to remove part of his right lung.