Princess Aiko, the only child of Emperor Naruhito and Empress Masako, began working at the Japanese Red Cross Society on Monday.
"I feel that I have taken my first step as a working adult," the princess, 22, told reporters in front of the main entrance of the organization's head office in Tokyo's Minato Ward.
The imperial couple told the princess in the morning to work hard, she revealed.
"I want to make efforts in order to get used to the workplace quickly and be of service to everyone," the princess said.
According to aides, Princess Aiko received a notice concerning her appointment from Japanese Red Cross Society President Atsushi Seike earlier in the day.
The princess will work at the division in charge of training and promoting volunteers, while also conducting official duties as an imperial family member. Princess Aiko graduated from Gakushuin University in Tokyo in March.