From his first day at the Third High School through to the very end of his career at Dokkyo University, Doi's teaching style, through his unique presence and worldview, is said to have truly inspired his students and drew them in.
三高時代から晩年の獨協大学まで、その授業風景は学生達の魂を揺り動かし巻き込む独自の風貌と世界があったといわれる。