According to the Japanese Embassy, the second son Emperor Akihito and his family will be hosted by Slovenian President Borut Pahor.
They will attend a ceremony marking the anniversary of diplomatic relations, but the visit will also include sightseeing of attractions like the Postojna cave.
The prince, his wife and three children are currently in Croatia, where they were received by PM Zoran Milanović today and are to be hosted by President Ivo Josipović in the evening.
The Japanese imperial family represents the country in international relations.
Prince Akishino (born in 1965) is the second in line for the Japanese throne and his son (born in 2006) is the first and only male member of the imperial family born after Akishino.