Through his loyalty and devotion to study and training, Ennin earned the deep affection of Saicho, who was trying to establish the Tendai Sect in the face of a resurgence of Nara Buddhism and the prosperity of Shingon Esoteric Buddhism.
奈良仏教との反撃と真言密教の興隆という二重の障壁の中で天台宗の確立に立ち向かう師最澄に忠実に仕え、学問と修行に専念して師から深く愛される。