Concerning when Kukai actually entered the Buddhist priesthood, there were the following two views: One was that he became a priest under priest Gonso at Makionosan-ji Temple in 793 at the age of 20, and the other was that he became a priest at the age of 25.
空海の得度に関しては、延暦12年（793年）に20歳にして勤操を師とし槇尾山寺で出家した、という説、あるいは25歳出家説が古くからとなえられていた。