The movie begins with the mysterious death of a journalistic photographer named Kim Cheol-hun. Veteran police detective Park (Kim Seung-ho) teams up with a young, intellectual detective (Kim Seong-ok) to investigate the people surrounding Kim. His landlord, his mother, and his younger sister offer no substantial clues. Finding a letter to Kim from novelist Han Jeong-wu, the detectives meet with Han, who tells them about a novel entitled The General's Mustache that Kim wrote. The novel tells the story of a great general who liberates his nation. The people grow mustaches like the general's as a tribute to him, but the protagonist refuses to do so and becomes an outcast. After talking to Han, the detectives find nothing suspicious about him. Instead, they go to former dancer Sin-hye (Yoon Jung-hee), who used to live with Kim, and hear the details about his life. According to Sin-hye, Kim was a romantic, but he could not adapt to reality. Sin-hye had fallen for his romantic sensibility, but eventually she tired of him and left him. Kim's death occurred shortly afterwards. The police rule his death a suicide.