Kukai, who had been a lay believer, immediately entered into the priesthood at Kaidan-in of Todai-ji Temple, in going to Tang; he then received the religious precept and was appointed as Rugakusho (an overseas student) to study abroad for twenty years.
空海は在家であったが、渡航に当たって急遽、東大寺戒壇院で出家し、戒律を受け、20年の長期留学を目的とする留学生（るがくしょう）に任命された。