Mayumi, the secretary to the president of a securities company, also serves as the president's personal partner. One day, she is asked to entertain Kishii, a stockbroker and acquaintance of the president, and heads to a hotel. After entertaining him in her own style, Kishii tells Mayumi about the excitement of stocks and decides to try buying some herself. She consults her ex-boyfriend, Kobayashi, who studies stocks, about her friend's intention to buy some. One day, Mayumi gets some information from the woman Kobayashi is currently dating and plans to make a fortune with him...