Japanese Princess Yuriko, the oldest member of Japan's imperial family, passed away at 101. She died due to old age, possibly pneumonia, after a year marked by health challenges, including a stroke. The princess, known for her charitable work, was the great-aunt of Emperor Naruhito and the widow of Prince Mikasa.Japanese Princess Yuriko, the oldest member of Japan's imperial family, passed away at 101. She died due to old age, possibly pneumonia, after a year marked by health challenges, including a stroke. The princess, known for her charitable work, was the great-aunt of Emperor Naruhito and the widow of Prince Mikasa.