Yi Bangja (, 4 November 1901 – 30 April 1989) was the wife of Yi Un, the last Crown Prince of Korea. Birth Born Princess Masako of Nashimoto (), she was the first daughter of Japanese imperial family member Prince Nashimoto Morimasa, the seventh son of Prince Kuni Asahiko and his wife, Princess Itsuko, a daughter of Marquis Naohiro Nabeshima. She was a first cousin of Empress Kōjun of Japan. On maternal side, she was also a first cousin of Princess Setsuko. Marriage Princess Masako was a leading candidate to wed the crown prince of Japan, the future Emperor Hirohito. Other candidates included Princess Nagako of Kuni (who became the future Empress Kōjun), and Tokiko Ichijō, a daughter of Prince Ichijō Saneteru. The possibility of infertility and the feeble political influence of her family were among the reasons she was removed from the list of candidates. However, Princess Masako was selected instead to wed Crown Prince Euimin of Korea who had been held by Japanese government under the pretense of studying abroad in 1917. The wedding was held on 28 April 1920, at the Korean royal residence in Tokyo. Princess Masako was still a student at the Girls' Department of the Gakushūin Peers' School at the time; her new title became Her Royal Highness Crown Princess of King Yi (). In addition, the title she received from birth, Princess Masako, still retained after she married. Despite an unfavorable fertility diagnosis prior to her marriage, she gave birth to a son, Prince Jin, on 18 August 1921. However, Prince Jin died under suspicious circumstances when she visited Korea with her husband on 11 May 1922. On 24 April 1926, Princess Masako received the formal title Her Royal Highness Princess Masako, Queen Yi () when the Emperor Sunjong, the elder brother of Crown Prince Euimin, died. Under the terms of the Japan–Korea Annexation Treaty, the Korean royal title was demoted from that of "Emperor" to "King" and Crown Prince Euimin was never formally crowned as the monarch of Korea; therefore, Princess Masako would later be addressed as "Bangja, Crown Princess Euimin" in Korea. On 29 December 1931, she gave birth to a second son, Yi Ku. Life as last Crown Princess of Korea After the end of World War II, all former royal and peerage titles were abolished by the American occupation authorities; ever since, Princess Masako took the Korean name Yi