Princess Aiko, the daughter of Emperor Naruhito and Empress Masako, is visiting the 2025 World Expo in Osaka for the first time since the event started in mid-April.
Princess Aiko was met by Osaka Governor Yoshimura Hirofumi when she arrived at an airport near the expo site on Thursday before noon.
The princess visited the Japan Pavilion in the afternoon to start her planned two-day visit.
She looked at a huge system called a photobioreactor that uses many tubes to cultivate microalgae through the process of photosynthesis.
Princess Aiko then went up to the Skywalk deck on the roof of the Grand Ring, a huge structure built as the symbol of the expo. She waved to visitors, who cheered in response.
An official attending the princess quoted her as saying the ring’s circumference of 2 kilometers felt much longer when she walked around it, and that her mother told her the same thing after she visited the expo.
Princess Aiko’s next stop was the pavilion sponsored by the Federation of Electric Power Companies of Japan.
She was shown around the facility, wearing a wireless device around her neck. She also took part in a game designed to help visitors understand the basics of nuclear fusion.
The princess then visited the pavilion operated by the Japanese Red Cross Society. She works at the organization, and Empress Masako serves as its honorary president.
Princess Aiko watched a video about natural disasters, conflicts and other humanitarian crises. She then read messages left by visitors at the pavilion.