The story is about M. Loisel, who debuts as a vain and superficial character. Her vanity ultimately leads to both her misfortune and her personal character development. The writer describes her in the following passage:
She had no dresses, no jewels, nothing. And she loved nothing but that; she felt made for that. She would so have liked to please, to be envied, to be charming, to be sought after.
Mme. Loisel is never content with what she has. She covets the expensive belongings of her rich friend and other privileged people. On the other hand, her husband is grateful for what they have and sees the positive of each situation. For example,
When she sat down to dinner...opposite her husband, who uncovered the soup tureen and declared with an enchanted air, "Ah, the good pot-au-feu! I don't know anything better than that," she thought of dainty dinners, of shining silverware, of tapestry...
In other words, she thought of all the things she does not have but wants, while her good-natured husband thinks how delicious their simple dinner will be.
M. Loisel excitedly brings home an invitation to a fancy ball, naively expecting that his wife will be thrilled. He clearly went out of his way to get the invitation expressly to make her happy. He says, “I had awful trouble to get it. Everyone wants to go.” To his surprise, she lacks gratitude and focuses on why she cannot attend the ball. She would need 400 francs to purchase an acceptable dress.
Her generous and self-sacrificing husband is saving exactly that amount to purchase a new gun. Without thinking twice, he gives up his dream and hands the money over to his wife.
Finally, after Mme. Loisel loses the necklace, he contributes his inheritance and scrimps and saves along with her to repay the loan they used to purchase a replacement, even though none of this was his fault.