Japanese Crown Prince Naruhito (L) is greeted by his wife Crown Princess Masako (R) and their daughter Princess Aiko at the Crown Prince's Residence in Tokyo on June 25, 2011.

 Crown Prince Naruhito returned to Japan from Berlin the same day after completing his four-day official trip to Germany.

In this picture released by the Imperial Household Agency on January 1, 2011, Crown Princess Masako, Crown Prince Naruhito, Emperor Akihito, Empress Michiko, Prince Akishino, Prince Hisahito, Princess Kiko (L-R in front row) and Princess Mako, Aiko and Kako (L-R in back row) pose for the annual official photo session for the new year at the Imperial Palace in Tokyo in this December 14, 2010 picture.

In this photo taken on Thursday, Dec. 2, 2010 and released by the Imperial Household Agency of Japan, Crown Prince Naruhito, left, Crown Princess Masako, right, and their daughter Princess Aiko, holding her cat, pose with their dog Yuri during their photo session at their residence Togu Palace in Tokyo. Masako turns 47th birthday Thursday, Dec. 9, 2010.

Japan's Princess Aiko smiles at her Togu Palace residence in Tokyo November 23, 2010, in this photo released by the Imperial Household Agency of Japan. Aiko, daughter of Crown Prince Naruhito and Crown Princess Masako, turned 9 on December 1, 2010. Picture taken November 23, 2010.

Japanese Princess Aiko (C), daughter of Crown Prince Naruhito dances with fellow students at the Gakushuin elementary school for her school's athletic festival in Tokyo on October 11, 2010. Crown Prince Naruhito and Crown Princess Masako attended the festival.

Crown Prince Naruhito, Princess Masako and Princess Aiko at Izukyu Shimoda station

Japanese Crown Prince Naruhito (L), his wife Crown Princess Masako (R) and their daughter Princess Aiko (C) are welcomed by well-wishers upon their arrival at Izukyu Shimoda station in Shimoda, central Japan, August 4, 2010. The three will spend their summer holidays at the Suzaki Imperial Villa located in the city.