The novel’s primary tension derives from Cassia’s internal conflict between her personal desires and her family’s expectations. Since she was a little girl and lost her mother, Evette, Cassia has been desperate to please her grandparents and aunts. She has chosen to devote herself to the family business both because she values the arts of face-reading and matchmaking and because she wants to avoid causing her family pain, but this undying devotion to Halmoni, Halabuji, Emoni, and Sunny has meant sacrificing her own desires and dreams.

Cassia’s competing relationships with Ellis and Daniel reveal her struggle to balance her competing personal and familial desires. Finding and marrying one’s “fated” love is a family tradition that (Cassia believes) her mother flouted, resulting in estrangement from her family and ultimately death. Knowing her grandmother’s devastation over her mother’s failed marriage and subsequent death, Cassia is determined not “to let her down,” not to “fill her life with any more pain” (143); to avoid disappointing Halmoni any further, Cassia consistently prioritizes Halmoni’s desires and happiness over her own. This is why she throws herself into her new relationship; Daniel satisfies all of her family’s expectations for her life, and not merely because he is her soulmate. Rather, Daniel’s Korean heritage associates him with what soulmates represent to Cassia’s maternal relatives, face-reading and matchmaking being cultural legacies intimately connected with the family’s Korean heritage. Cassia’s family may not explicitly pressure her to marry someone from a similar cultural background, but the narrative conceit of fated love becomes a means of symbolically exploring this dynamic in diaspora communities.   

Ellis, by contrast, represents Cassia’s uncharted personal desire, unhindered by her family’s influence. Yet choosing him feels like an impossibility to Cassia: “Love is never a duty, but for my family it kind of is. There’s expectation there—it might be tied to the idea of me finding happiness, but my family’s business relies on that happiness” (198). Ellis is not her soulmate, and his multiethnic background (Jewish and Chinese) locates him firmly within the American “melting pot.” Cassia is thus terrified that if she pursues her own path, she will jeopardize her relationships with her family and her future with the family business.

Nevertheless, this is what Cassia does at the end of the novel, choosing to follow her heart instead of her family’s expectations. At the same time, she maintains links to her heritage, most notably in her role heading the family business. Indeed, that Halmoni makes Cassia One & Only’s new president symbolically signals her recognition that cultural and familial traditions can evolve to accommodate individual aspirations while still remaining strong and meaningful.