The title character of the film, played by Nobuko Miyamoto, is a government tax investigator who employs various techniques to catch tax evaders.
The director reportedly was inspired to make the film after he entered a much higher tax bracket after his success with The Funeral.
One day she persuades her boss to let her investigate the owner of a string of love hotels who seems to avoiding tax, but after an investigation no evidence is found. During the investigation the inspector and the inspected develop an unspoken respect for each other.
She is promoted to a government tax inspector. When the same case reappears she is again allowed to investigate. When a series of raids against his interests are launched, she accidentally comes across a hidden room containing vital incriminating evidence.
On the same day, she helps the man with his relationship with his teenage son.
Six months later the two meet again. The man is tired after daily interrogations. She tries to persuade him to surrender his last secrets for the sake of his son. After she declines an offer to live with him, he cuts his finger and writes the name of the secret bank account in blood on a handkerchief of hers that he saved from the first time she investigated him.