On the penultimate day of his long-cherished trip, Francis had an emotional encounter with survivors of that fateful day on March 11, 2011, when a 9.0-magnitude earthquake followed by a 17-metre (56-foot) high tsunami devastated much of northeastern Japan and killed nearly 16,000 people.
The 82-year-old pontiff paid tribute to those who rushed to the assistance of the victims “with outpourings of prayers and material and financial aid.”
“We should not let this action be lost with the passage of time or disappear after the initial shock; rather, we should continue and sustain it,” Francis said.
The wave swept away everything before it, washing away people, buildings and farms, but also damaging cooling systems at the Fukushima Daiichi nuclear power plant, sparking the worst nuclear disaster since Chernobyl.
Nearly half a million people fled their homes in the first days after the quake and even today, roughly 50,000 remain in temporary housing.
The pope heard harrowing testimony from survivors of that day, such as Toshiko Kato, who headed a Catholic kindergarten and lost her home in the tsunami.
“I remember that when I stood in the rubble where my home had been, I was thankful for being given life, for being alive and for just being able to appreciate it,” she told the pope.
“Through this earthquake, I received much more than I lost. Many people from all over the world opened their hearts and I was able to find hope from seeing people come together to help one another.”
However, the head of the world’s 1.3 billion Catholics noted that some of those feel “forgotten” and face ongoing issues of contaminated land and the long-term effects of radiation.
The pope stopped short of intervening in the debate over nuclear power in Japan, merely noting that bishops in the country have called for atomic plants to be shelved.
“In turn, this involves, as my brother bishops in Japan have emphasised, concern about the continuing use of nuclear power; for this reason, they have called for the abolition of nuclear power plants.”
In 2016, the Catholic Bishops’ Conference of Japan made a statement saying: “What Japan has experienced in the five-and-a-half years since the Fukushima disaster convinces us that we must inform the world of the hazards of nuclear power generation and appeal for its abolition.”
Later Monday, the pope, who has described his feelings of “fondness and affection” for Japan, will hold a Mass in the huge Tokyo Dome stadium and hold private talks with Japan’s new Emperor Naruhito and Prime Minister Shinzo Abe.
There are also rumours he may meet a death row convict and make comments criticising the death penalty, which is carried out in Japan with significant public support.
The emotional centrepiece of his four-day trip was his initial trip to Nagasaki, a city forever associated with the dropping of a nuclear bomb that eventually killed at least 74,000 people.
There, the Argentine lashed out at the concept of nuclear deterrence and prayed in the rain for the victims of those killed in the “unspeakable horror” of the bomb.
He then travelled to Hiroshima, the first city to suffer an atomic attack, where he denounced as a “crime” the use of nuclear power as a weapon.
In both cities, he met people who survived the bombings, and listened to their tales of the horror.
The final day of his trip on Tuesday takes in meetings with young students at Sophia University before he concludes his Asian tour.
The first leg of the tour was in Thailand — like Japan, a country with a small Catholic minority. There are an estimated 440,000 Japanese Catholics.