Megumi is a top sales person at the handbag section of a department store. Many people admire, and sometimes even envy, Megumi for her beauty and outstanding skills to sell products to customers. However, Megumi secretly suffers from a complex: she is flat-chested and was once nicknamed "kabe onna" (wall woman) by her former classmate. One day, a new sales person named Marie joins Megumi's department. Unlike Megumi, Marie is extremely busty as if she's carrying mounds (yama) on her chest. On top of her great bosoms, Marie also has her own special way of effortlessly selling the products to the customers. Though feeling a little threatened by Marie at first, Megumi soon realizes that they have more things in common than anybody else: they both take pride in their career and dedicate themselves to helping their customers. Through numerous obstacles, Megumi and Marie foster special friendships with each other.