
This incident makes Sensei very distrustful of other people, but when he moves in to board with a widow, Okusan, and falls in love with her beautiful daughter, Ojosan, he becomes more outgoing and less melancholy. Orphaned at a young age, Sensei allows his beloved uncle to take care of his inheritance while he attends university in Tokyo, but then he discovers that his uncle has cheated him of much of it. In Sensei's testament, the secretive man reveals the past events that made him lose all hope in himself and the rest of humanity. Immediately, the narrator leaves his father's deathbed and rushes to Tokyo.


As the family awaits the father's death, the narrator receives a long letter from Sensei at the end of which he states that he is going to die. However, the next time the narrator is called back home due to his father's illness, it turns out to be much worse, to the point that his father goes through a terrible physical decay and seems moribund. Soon afterwards he returns to Tokyo and finishes his university education, all the while talking with Sensei. When the narrator receives word that his father's illness has worsened, he leaves Tokyo for his provincial hometown, where he finds that even though his father actually seems rather well there is a painful distance between him, an educated and urban young man, and his family. Although Sensei gives the narrator a great deal of advice on life, he is hesitant to reveal the details of his own dark past from which he has acquired those lessons, which frustrates the student's curiosity and earnestness to learn. For reasons that he himself is not completely aware of, the narrator is drawn to Sensei and so while staying in Tokyo for his university he often visits Sensei and his wife at their quiet home to talk with Sensei.

In early 20th century Japan, the narrator, a university student, meets an enigmatic and aloof older man whom he calls Sensei.
