For this unusual shift in the world’s oldest monarchy, our Tokyo bureau chief took a deeper look at the royal family, which has faced near extinction, intrigue, drama and disappointments.

Part 1: After World War II, when Akihito was a 12-year-old crown prince, international pressure was mounting to prosecute Japan’s royal family, and the fate of the monarchy hung in the balance.

Part 2: In 1975, Akihito and his wife, Michiko, visited a seething Okinawa. His mission: to atone for Japan’s wartime sins.

Part 3: A decade later, the future of the royal family was again at stake, this time hinging on Naruhito’s finding a wife — and fathering a son. He fell in love with a diplomat and, despite the country’s impatience, waited six years for her.

Part 4: To marry Naruhito, Masako Owada gave up everything: career, travel, independence. But all the country seemed to care about was whether she could give birth to a son.