Crown Prince Fumihito and his wife Crown Princess Kiko left Japan on Thursday for a tour of Poland and Finland marking the centenary of Japan establishing ties with the European countries.

The couple's tour is the first overseas trip by members of the Japanese imperial family since the May 1 ascension of Emperor Naruhito, the elder brother of the crown prince. It is also the couple's first official visit to the two countries.

While crown prince, Emperor Naruhito used a government jet for overseas visits, but Crown Prince Fumihito, now first in line to the throne, will fly commercial.

The Imperial Household Agency said he has not faced any trouble when flying on commercial airlines in the past.

The couple is expected to arrive in the Polish capital Warsaw on Thursday evening, flying via Frankfurt. They will make a courtesy call on Polish President Andrzej Duda, attend ceremonies and visit the city of Krakow during their stay.

They will move on to the Finnish capital Helsinki next Tuesday and meet with the nation's President Sauli Niinisto the following day.

During their visit to the Nordic country, the couple will visit a neuvola facility, part of the Finnish childcare system of the same name that has been garnering increased attention in Japan due to its potential to help address the country's low birthrate.

They will return to Japan on the morning of July 6, arriving at Narita airport.