Supplied photo shows Prince Hisahito at the National Agriculture and Food Research Organization in Tsukuba, Ibaraki Prefecture, on Aug. 2, 2023. (Photo courtesy of the Imperial Household Agency) (Kyodo)

Prince Hisahito, the nephew of Emperor Naruhito and second in line to the Japanese imperial throne, turned 17 on Wednesday as he continues to thrive in his second year of senior high school.

The son of Crown Prince Fumihito and Crown Princess Kiko is enrolled at Senior High School at Otsuka, University of Tsukuba, where he has been actively involved in his studies, club activities and events with his peers, including friends from outside his class.

Prince Hisahito is the first member of the imperial family in the postwar era to attend a high school unaffiliated with Gakushuin University, established in the 19th century to educate aristocrats. His father is known to favor a liberal education for his children.

According to the Imperial Household Agency, the number of subjects the prince is studying has increased, and his assignments have also become more challenging. It said that he also uses break times to ask teachers questions and that he and his classmates study by offering each other advice on how to solve problems.

A member of the school badminton club, his abilities have developed as he has practiced between classes. He also offers advice to first-year students who have recently joined the club.

In June, the prince took part in an excursion for second-year students where he observed research at the University of Tsukuba on insects and their relevance in agriculture and had the chance to use a microscope.

During his summer vacation, he made his debut in accompanying his father Crown Prince Fumihito on a regional visit as part of his official duties and attended various events, including the late July opening of a national culture festival for high schools in Kagoshima Prefecture, southwestern Japan.

In early August, he attended a lecture on rice genome analysis during a visit to the National Agriculture and Food Research Organization.

The prince continues to pursue his longstanding interest in dragonflies that developed in his elementary school years. He does related fieldwork, including on the grounds of the Akasaka Estate, where he lives with his family.

Prince Hisahito's two elder sisters -- former Princess Mako, 31, who married out of the imperial family in 2021, and 28-year-old Princess Kako -- are not in line to the Chrysanthemum Throne due to the Imperial House Law limiting heirs to males paternally related to the emperor.

Because Emperor Naruhito's only child is 21-year-old Princess Aiko, Prince Hisahito is second in line to the throne after his father. The only other remaining heir is the emperor's uncle, 87-year-old Prince Hitachi.