Supplied photo shows Princess Kako (L) and her elder sister Princess Mako at the Akasaka Estate in Tokyo on Dec. 4, 2020. (Photo courtesy of the Imperial Household Agency)(Kyodo)

TOKYO - Princess Kako, the niece of Japanese Emperor Naruhito, turned 26 on Tuesday, while spending much of her recent time at her residence in Tokyo and performing her duties online amid the novel coronavirus pandemic, according to the Imperial Household Agency.