With the object of discovering the male accomplice of Hideko, a bad girl, Michiko, a police-woman, disguises herself and infiltrates a gang. Then in a reformatory, under the name of Suzuko, she finds a certain girl who is familiar with Hideko and from her she approaches a woman, named Keiko. One day, at a beer-hall, the police-woman meets Keiko who just finished a secret narcotics transaction and asks her about Hideko. However, with the sudden appearance of Saburo, one of the gang, her search fails, and an exciting pursuit begins. Later Keiko is found dead.