However, Imperial Prince Osabe, the former crown prince and his half brother with the same father, and his mother, Imperial Princess Inoe, were gotten rid of due to the political fight, and the Emperor Kammu had a ceremony of the formal investiture of the Crown Prince on February 2, 773.
しかし、藤原氏などを巻き込んだ政争によって異母弟である前皇太子他戸親王とその母であった皇后井上内親王が突如廃されて宝亀4年（773年）1月2日に立太子。