Aiko, Princess Toshi (born 1 December 2001) is the only child of Crown Prince Naruhito and Crown Princess Masako of Japan.

On 1 December 2001, the Crown Princess gave birth to a baby girl. lt was their first child after 8 years of marriage for the then 37 years-old crown princess and the 41 years-old crown prince. The baby was born at 2:43 PM and was 49.6 centimeters tall and weighed 3,103 grams. The crown prince was in the delivery room during the birth and the crown princess was attended by a 12-person medical team with four doctors.

Princess Aiko began her education at Gakushuin Kindergarten on April 3, 2006. She left kindergarten on March 15, 2008. On 18 March 2014, Princess Aiko finished at Gakushuin elementary school and on 6 April 2014 she entered Gakushuin Girl’s Junior High-school.

On her eighth birthday, it was revealed her interests include but are not limited to: writing Kanji characters, calligraphy, jump rope, playing piano and violin, and writing poetry.

In early March 2010, Aiko began to stay home from school due to, along with other girls, being bullied by her elementary school classmates. Aiko returned to school on a limited basis on May 2, 2010. After returning to school, a senior palace official said that she would attend a limited number of classes accompanied by her mother, upon advice from a doctor at the Crown Prince’s household.

In November 2011, Aiko was hospitalized with pneumonia