After graduating from university, Fujiko finds employment at an advertising agency. She is assigned to the sales department, where she works as a subordinate to Masumura, an elite salesman with a promising future, who is married to the company president's daughter. The two eventually become close and start a relationship. While she is happy to have such a handsome boyfriend, her position as his mistress makes her feel unstable. One day she have sex with Masumura in the office, but she is caught in the act by Sachi, who competes with Masumura for the top spot...