Throughout the reading of kokoro, the work "loneliness" occurs to me pretty often. It refers to both the narrator's loneliness and Sensei's. Loneliness might not be totally isolated from others, but keep one's self's real thoughts away from others. In the narrator's case, he is confused what to do after graduation. Even before graduation he is also puzzled by the thesis. He is a really unsured person. He is unsure about his future. However, when he faces his parents, he finds himself speechless of his real feeling. He surrenders and pretends to do what they think he should do, finding a well paid job and earning reputations for them. He is lonely at his side about his real feeling. His dealing with Sensei may be a significant of some kinds of similarities. Sensei's loneliness at first is presented to be a mystery. His loneliness is due to not trusting anyone, as well as himself. Sensei is always holding himself back from others. The secret then comes to the air in the last part of the book. Sensei, before he's going to kill himself, writes in the letter to the narrator. Sensei's experience of being cheated by his own uncle comes first. It is the reason that he thinks no one can be trusted. But later on, he found himself being this kind of person that he disgusted mostly. Love and jealousy drove him deceiving his friend, K. And fatally K committed suicide. With deep sorrow and regret, he kept the secret of the deceiving and held himself back from others, as well as his wife. He loves his wife, but the secret also pulls him away from her. Meanwhile self-disgusting makes him not to trust himself as well. Finally when Meiji Emperor died, the ending of his era makes Sensei's loneliness becoming more deeper. Hence, to end the loneliness is to kill himself.