Princess Aiko, the only child of Crown Prince Naruhito and Crown Princess Masako, turned 16 on Friday, enjoying high school life and striving to better fulfill her role as a member of the imperial family.

Over the past year, she has accompanied her parents on official duties and met members of foreign royal families. Her health has improved since she appeared fatigued in fall last year.

During the May holidays, the princess watched a game of wheelchair basketball with her parents and showed a strong interest in the sport.

She also accompanied her parents when they greeted Swedish Crown Princess Victoria, Danish Crown Prince Frederik and Crown Princess Mary, as well as Bhutan Princess Sonam Dechan Wangchuck during their visits to Japan, according to the Imperial Household Agency.

On the anniversaries of Japan's surrender in World War II and the March 11, 2011, earthquake and tsunami in northeastern Japan, the princess observed moments of silence. She also listened to her parents' accounts of their visit to disaster-hit Miyagi Prefecture in November.

The princess has attended Gakushuin Girls' Senior High School since April, after graduating from the junior high school located on the same campus in Tokyo.

She was absent from junior high school for a month and half from late September last year due to fatigue, but her condition has improved over the past year, according to the agency.

The princess does not engage in any club activities, but she has actively taken part in athletics meets and cultural festivals. She often talks to her parents about her school life, the agency said.

Princess Aiko is not eligible to ascend the throne, which is restricted to males under Japan's Imperial House Law.