Hidaka Eisuke used to be a hotshot brain surgeon with a promising future. He even married a professor's daughter, Hiroe to stay ahead in the hospital's career track. As time passed, he no longer felt the significance of marriage and neglected his family. Meanwhile, his son died of an illness. Blaming herself for his death, Hiroe committed suicide. At the same time, Hidaka accepted responsibility for a medical error in the hospital and resigned as a doctor.

With all hope lost, he became a recluse and eventually degenerated into a homeless man. Suspected by the police to be the culprit in a case of arson in one of the streets he wanders, Hidaka is questioned. At the discretion of a detective, Hidaka's former girlfriend, the psychiatrist Nagasawa Miwako, arrives as his guarantor. As if by fate, Hidaka meets Kusanagi Masato, a youth that he had saved from sexual abuse 12 years earlier, on the streets and begins to feel fatherly. Masato has an uncanny ability to "hear people crying in their hearts". As Hidaka and Masato support each other, Hidaka finds the hope to live, but gradually struggles with the possibility that Masato may be the criminal behind the spate of serial murders targeting the socially vulnerable on these streets...