Crystal Hana Kim's debut is a bold mashup of wartime novel and love-triangle romance.

Two distant cousins — Jisoo, raised in a wealthy enclave of Seoul, and Kyunghwan, a better student, but one of lesser means — long for the same girl: the rebellious, outspoken Haemi, who lives with her widowed mother and sickly brother Hyunki. Between 1951 and 1967, Kim charts personal and national turmoil with equal interest, offering exquisite scenes of marital discord as adeptly as the inner workings of a refugee village or field hospital.

Although the war is inescapable for her characters, Kim gives Haemi and Kyunghwan an adolescence with elements of timelessness: They sneak out in the evenings on a bicycle to drink in bars; Haemi tints her fingernails; they argue and flirt. When Haemi agrees to marry Jisoo — who courts her by providing medicine for tubercular Hyunki — Kyunghwan never quite recovers.

Their eventual reunion, as well as the brief affair it engenders, feels somewhat inevitable, and raises a question about the paternity of Haemi's fourth child.

The story urges its readers to sympathize by making Jisoo unworthy of Haemi — violent, jealous, frequently drunk — although the complexity of these relationships could thrive without leaning on objective flaws.

Kyunghwan entrusts a letter of great import — his request that Haemi leave Jisoo to be with him — in the hands of her eldest daughter, Solee, who suffers her own infatuation with Kyunghwan. Solee decides to shred the message instead of delivering it.

Kim's prose is most potent and visceral in its depictions of literal hunger. She allows hunger to seep into conversations about other subjects, giving it its rightful omnipresent quality. Kyunghwan recalls days "when we used to strip pine trees as children to get to their edible inner bark"; later, dining with a much younger woman, he notes, "[w]hen she found an ox bone, she didn't wrest off the meat but sucked on it whole." Haemi describes hunger so great "we'd eat the lees from the distillery."

Later, when her four daughters complain about the lackluster meal she prepares, she tells them, " 'Food is for nourishment, to keep you from going hungry. Taste is second.' " The differences among the generations — those born before, during and after the wars — are vividly described and are the source of small tensions (strict landlords, horrified in-laws) that enhance the novel's authority.

When Hyunki, a college student, attends a protest against Haemi's advice, the novel's tone shifts and becomes increasingly ominous. Hyunki dies. Jisoo leaves. Upon realizing that Solee destroyed Kyunghwan's letter, Haemi initiates a disturbing confrontation. Sorrows compile at an increasing pace as the novel closes, but its finest moments are in its everyday troubles in a landscape wracked by war.

Jackie Thomas-Kennedy's writing has appeared in Lenny Letter, Narrative, Crazyhorse, the Millions, Harvard Review and elsewhere. She held a 2014-16 Stegner Fellowship at Stanford University.

If You Leave Me
By: Crystal Hana Kim.
Publisher: William Morrow, 417 pages, $26.99.