In the mid '90s, three female high school graduates working in an office take English classes together to earn promotions. Then, they team up to uncover corruption within their company.

In 1995, Lee Ja-Young, Jung Yoo-Na and Sim Bo-Ram are friends and co-workers at Samjin Company. They have been working there for 8 years, and are good at their work, but, because of their only high school educational backgrounds, they are still at the lowest position in the company. One day, the company announces that any employee that attains a score of 600 or higher on the TOEIC (Test of English for International Communication) exam will receive a promotion to assistant manager.—Canon y mus