Hee-kyeong (Lee Eum) and Seung-ah (Lee Jung-kyung) are cosmetics store workers. Excluding unpleasant emotions and depressive energy, the two greet guests as the happiest employees in the world. One happy day, a call comes in asking for a cosmetic return. Jeong-ran (Yoon Ga-hyun), a customer who complains that she bought a cosmetic product to prevent wrinkles around her eyes, but she has more wrinkles around her eyes. Jeong-ran, who came to the store because of the unsatisfactory service, starts demanding a refund through abuse. Hee-kyeong and Seung-ah, saleswomen who have to smile whether it rains or snows, complain about Jeong-ran's constant attitude towards customers. The mart branch manager Sang-pil (Ahn Nae-sang) asks for help, and Jeong-ran expresses a sincere apology to Seung-ah. She gets down on her knees and asks for forgiveness... The best truthful customer since the opening of the mart. Will Hee-kyeong and Seung-ah be able to laugh until the end?