Photo/IllutrationEmperor Akihito and Empress Michiko leave JR Tokyo Station on April 17 to visit Ise Jingu shrine in Ise, Mie Prefecture. (The Asahi Shimbun)

Emperor Akihito, along with Empress Michiko, on Wednesday started a three-day pilgrimage to Ise Jingu shrine, the holiest site in Japan's Shinto religion, as part of a series of rituals for his abdication this month.

This is their last trip as emperor and empress to the shrine in central Japan, dedicated to sun goddess Amaterasu Omikami, mythical ancestress of the emperor.

Prime Minister Shinzo Abe, who escorted U.S. President Barack Obama and other Group of Seven leaders to the shrine on the sidelines of the G-7 summit in 2016, saw Akihito and Michiko off at a Tokyo railway station.

The royal couple are traveling with a legendary sword and a jewel, encased in black boxes and carried by chamberlains. The two items, together with an ancient mirror, are known as the Three Sacred Treasures of Japan and symbols of the imperial throne.

Akihito, 85, will step down on April 30, the first abdication of a sitting Japanese emperor in two centuries, and will be succeeded the next day by his elder son, Crown Prince Naruhito, 59.