Crown Prince Fumihito, Crown Princess Kiko and their 12-year-old son Prince Hisahito arrived in Bhutan on Saturday for a private family trip.
It is the first overseas trip for the junior high school student, who became second in line to the Chrysanthemum Throne following his uncle Emperor Naruhito's enthronement in May.
The two princes took separate flights as a precautionary measure while Crown Princess Kiko flew with her son, who is currently on summer holiday.
The three arrived in the South Asian country via Thailand, receiving a welcome from members of the Bhutanese royal family at Paro airport.
The family will meet Bhutanese King Jigme Khesar Namgyel Wangchuck over lunch on Monday in the capital Thimphu, according to the Japanese Imperial Household Agency.
They will watch a demonstration of archery, Bhutan's national sport, on Tuesday. Visits to temples and museums are also scheduled during their stay before they return on Aug. 25.
Japan has maintained a close relationship with Bhutan since the two countries established diplomatic ties in 1986. Crown Prince Fumihito and Crown Princess Kiko traveled to the country in 1997, while the king of Bhutan visited Japan as a state guest in 2011.
In 2017, Princess Mako, elder sister of Prince Hisahito, paid an official visit to Bhutan.© KYODO