In the tenth month of the tenth year of Emperor Tenji, the emperor fell gravely ill. He sent Soga no Yasumaro to summon his younger brother, the crown prince (Prince Oama), to his bedchamber. Yasumaro had long been friendly with the crown prince, and he glanced back and whispered, "Be very careful how you answer." The crown prince sensed a plot and was on his guard.
When the emperor said he wished to pass the throne to him, the crown prince declined: "Unfortunately I have always been sickly and could never keep the realm safe. I beg you, entrust the realm to the empress and make Prince Otomo crown prince. From today I wish to leave the world and practice the Buddhist way for Your Majesty's sake." The emperor allowed it. That same day the crown prince shaved his head south of the palace's Buddha hall and became a monk.
On the nineteenth of the tenth month, the crown prince set off for Yoshino. The ministers of the left and right saw him as far as Uji. Someone said, "This is like giving wings to a tiger and letting it loose in the wild."
In the twelfth month Emperor Tenji died at the Omi palace. In the fifth month of the following year, word reached Oama in Yoshino that the Omi court was gathering laborers from Mino and Owari and arming them, and that it had posted watches along the roads from Omi to Yamato and was stopping food from being carried to Yoshino. Oama said, "I gave up the throne and withdrew so that I might tend my illness alone and live out my days. Yet now disaster is coming for me. How can I let myself be destroyed in silence?"
On the twenty-fourth of the sixth month, Oama at last left Yoshino. It was so sudden that there was no horse to ride, and he set out on foot. His consort, Princess Uno-no-Sasara (later Empress Jito), rode in a palanquin, and Prince Kusakabe, Prince Osakabe, some twenty attendants and a dozen or so ladies followed. This was the beginning of the Jinshin War.