The book begins with Zauner talking about how the store H Mart reminds her of her mother, Chongmi. She details various foods on the shelves and talks about how food was a significant aspect of the bond that they shared. She says that now she often cries in the aisles of the store, as she is no longer able to call her mother to ask about recipes and ingredients because she has passed away. She talks about how H Mart works as a touchstone for other people before concluding on a note about how the store is inextricably linked to her personal life and her memories of her mother and culture. She goes on to discuss her mother's death as well as her earlier childhood in Eugene, Oregon. She describes the intensity of her mother's love for her which she saw manifesting in her sometimes harsh and brittle manner towards her when she misbehaved. She says that from a very young age, food proved to be an essential link between her and her mother.
In the third chapter, she talks about visiting Korea as a child. She depicts the various members of her family as well as the activities she enjoyed doing in Seoul, like admiring the bright labels on food packages and being read to. She recounts the wonder with which these events filled her. She also talks about how she was constantly struggling with the complexity of being both white and Korean and never feeling completely comfortable. In the next chapter, she talks about how when she found out her mother was ill she was just out of college and living in Philadelphia. At the time, she was working as a waitress and playing in a band called Little Big League. Before meeting up with a college friend in New York, Zauner receives a call from her mother who informs her they have discovered a cancerous growth in her stomach. Her boyfriend Peter drives up from Philadelphia to be with her after the call and comfort her.
In the fifth chapter, Zauner details going home to be with her family. She expresses a desire to be with her mother while she is going through treatment, but her mother is concerned this will only stoke old tensions between them. She talks about her experience of high school and her growing fascination with music. She learns guitar and performs at an open mic. Initially supportive, her mother grows dismissive when she talks about trying to do music as a career. Their relationship fractured further during this time and they frequently had intense disagreements. Zauner saw her return as a potential way to make up for these years of trouble. She comes back and feels frustrated with her father's unreliability. She notes both his history of infidelity as well as his alcoholism. She contrasts the tone of this homecoming with her teenage struggles, noting that before she wanted to escape into darkness, but now she wants to ward the darkness away.
In the initial days of her mother's treatment, Zauner began to stock up on groceries, hoping that she could cook her mother's favorite meals. She makes a small dish that her mother does not feel well enough to eat. Her mother's health takes a turn for the worse as she becomes delirious and has to be rushed to the emergency room. Chemotherapy leaves her mother feeling drained and physically weak. Some of Zauner's mother's friends come to stay and take care of her. One of them, Kye, takes over the role of cooking, which Zauner has mixed feelings about, as Kye's presence makes her feel excluded.
In the ninth chapter, Zauner discusses the deaths of some of her relatives and the profound impact they had on both her and her mother. Following her mother's completion of a second round of chemotherapy, she decides to return to Philadelphia. Her band goes on tour. She learns shortly thereafter that her mother's cancer has returned and that the odds do not appear promising. Zauner falls into intense despair and thinks about everything she will not be able to experience with her mother. Zauner flies to Korea with Peter and her mother and father for one last visit. Her condition only worsens, and, faced with the prospect of having to put her on a ventilator, they decide to return to America. Zauner decides that because time is limited, she wants to get married while her mother is still alive. Her boyfriend Peter agrees and they begin preparing for the wedding.
Zauner recounts the happy days of her early courtship with Peter, describing how they met and began their relationship. The wedding goes well and Zauner appreciates a fleetingly joyful moment in the midst of so much tragedy. Zauner's mother's condition continues to deteriorate. Kye leaves abruptly after a disagreement with Zauner's father. Her mother experiences intense pain and then falls almost entirely unconscious. She dies very soon after this and Zauner is completely devastated, feeling as though she will never experience happiness again. The family makes funeral arrangements and after the funeral, Zauner weeps.
Zauner and her father plan a trip to Vietnam. While she had initially hoped it would provide some necessary relief from their shared grief, the trip instead exacerbates tensions between them. After a particularly unpleasant dinner at a restaurant, they have an explosive argument and Zauner leaves the table to get away from her father. She goes to a karaoke bar and sings with a stranger, which makes her feel momentarily better. They return from the trip and appear to feel mutually relieved that it is over. Her father gets in a car accident and, after picking him up, she realizes she can't continue to also take care of him. Peter moves in with Zauner and her father and assists them with cleaning out the house. Zauner cooks a Korean porridge for herself and feels full for the first time in weeks.
Zauner returns to Philadelphia. She records a new album and works a job at a pizza restaurant. She decides to go to Korea and visit her relatives, Nami and Emo Boo. She becomes concerned about bringing up painful memories of her mother and speaking with them across a language barrier. However, she instead finds the trip to be intensely meaningful, as she reconnects with her familial past and important elements of her cultural heritage. At the end of the trip, she feels that she was able to experience all of the things her mother had wanted to show her before she passed away. Zauner applies for jobs in New York and lands one at an advertising company. At the same time, she derives comfort from making and eating Korean food, often watching instructional videos about cooking it.
Zauner's father sells their home and they move around some of their large furniture and appliances, including her mother's kimchi fridge. At Peter's family's home, where they have stored the fridge, Zauner finds a number of family photographs. She reflects on how her mother archived so much of her life and how she can hold onto these memories without them just being painful. She learns how to properly ferment kimchi and compares its preparation to the process of turning grief into remembrance. Her new band, Japanese Breakfast, gains some mainstream success and she goes on tour again with the album she recorded. They finish the tour in Seoul and Zauner has an emotional reunion with her relatives. At a karaoke bar on the last night of her visit, they sing "Coffee Hanjan," a song her mother loved.
