Princess Aiko, the only child of Crown Prince Naruhito and his wife, Princess Masako, graduated from Gakushuin Primary School on Tuesday.
The 12-year-old princess, who attended the commencement ceremony with the royal couple, is scheduled to enrolled at Gakushuin Girls' Junior High School in April.
Princess Aiko, who entered the primary school in 2008, stopped attending for a period in February 2010 when she was a second-grader due to worries about school life, and was escorted by Princess Masako until December 2011.
At the school, she joined the orchestra as a cellist when she was a fourth-grader and the basketball club in the following year.
She also studied English and received English lessons at Gakushuin Women's College every summer.
Motomasa Higashisono, one of the managing directors of Gakushuin School Corp., operator of Gakushuin schools, said the princess overcame her worries to attend school and grew up strongly.
