Saicho gained the confidence of the Imperial Court, but when Kukai came back the next year with all the teachings of Shingon Esoteric Buddhism, he gained the confidence of the Imperial Court instantly, and played an active role, and Saicho realized that what he had learned was only a part of Esoteric Buddhism, and made great courtesy to Kukai, and became Kukai's disciple at Jingo-ji Temple on Mt. Takao with other disciples of his own.
最澄は帰国して朝廷からの信任を得るも、その翌年に真言密教のすべてを修めた空海が帰国し、すぐに朝廷から信任を受け活躍すると、最澄は自身が学んできた密教は一部の傍系のものでしかないことに気づき、空海に礼を尽くし自らの弟子共々、高雄山神護寺において空海の弟子となった。