The 30-year-old Charlie is a moron whose intelligence level is only equivalent to that of a 6-year-old child. He worked as a cleaner in the bakery during the day, earning a meagre salary to support himself, and had to put up with malicious mockery of him. In order to improve his situation, he insisted on going to night school, but with little success. His teacher Alice extended a helping hand to him. To get his intelligence back to normal, Alice took him to Dr. Richard, a neurologist, and Dr. Anna, a psychiatrist, who were conducting an experiment on improving the brain. their experiment is to restore a dull brain to a normal level by surgery. Charlie decided to risk the operation, and it turned out to be very successful. his intelligence not only reached, but also far exceeded the level of normal people. he became a genius and fell in love with Alice. They had a wonderful and sweet holiday, which was the happiest day of Charlie's life. But accidents always happen. Richard and Dr. Anna's next study is to return the normal brain to its original dullness, and they hope that Charlie will work with them again. Although Charlie had strong dissatisfaction with the civilized society, he agreed to this absurd request. In the company of Alice.