The following version of this book was used to create the guide: Itami, Emily. Fault Lines. Phoenix Books, 2021.

Emily Itami's novel Fault Lines is written from the main character Mizuki's first person point of view. The narrative disrupts conventional notions of plot and form, employing both the past and present tenses. The following summary uses the present tense and a primarily linear mode of explanation.

Mizuki is a housewife living in contemporary Tokyo, Japan. Though she always wanted to be a mother, she never imagined herself living such a traditional, domestic life. When she was young, she took a trip to New York City. While there, she discovered parts of the world and of herself she never knew existed. Her relationship with her host family, the Michaelsons, opened her to new understandings of happiness and love. She also discovered a passion for singing during her trip, and decided to pursue the art as a career.

Shortly after returning to Tokyo, she secretly dropped out of school and got a job to pay for her ticket back to the States. When her mother found out, she practically disowned Mizuki. Despite her mother's disapproval and her father's disappointment, Mizuki returned to New York City. She spent the next three years here, trying her hardest to turn her dreams into reality. Because of how much she loved her independence and freedom, Mizuki was surprised when she began missing her home and family.

She returned to Tokyo and tried to continue singing. However, she soon realized how few opportunities she had in Tokyo. After a gig one night, Mizuki met Tatsuya. He complimented her performance, and they went home together. She had no intent of turning their one-night stand into a long term relationship.

In the early days of their marriage, Mizuki thought she had made the right decision. Then, when they had their children, Eri and Aki, Mizuki felt new versions of love and contentment she had never known before. However, the more consumed Tatsu became by his career, the more unhappy Mizuki felt.

Years later, Mizuki's unrest has augmented to such a degree that she attempts suicide. Afterwards, she realizes how absurd the attempt was. Yet the incident also challenges her to confront the reasons for unhappiness. Though she tries to reconcile the life she chose with the life she could have chosen, Mizuki remains emotionally divided.

Therefore, when she meets Kiyoshi, a handsome and interesting man, she feels an energizing sense of possibility. She and Kiyoshi soon begin an affair. Though she does not realize it, Mizuki is using Kiyoshi as a distraction from her true unrest. When they are together, Mizuki feels seen and understood. She also feels that happiness and freedom are possible again. Despite these positive and life-giving aspects of their dynamic, Mizuki also doubts her ability to abandon her husband and children.

When an earthquake hits while Mizuki is on the train with her children, she is forced into revelation. She saves herself and her children. The next day, realizing the importance of preserving what she has, and of protecting her family from heartbreak, Mizuki ends her affair with Kiyoshi. With time, she finds peace, beauty, and love in the life she has chosen.