Cheng Xiaoning, the daughter of the Cheng family, originally prepared to discuss engagement arrangements with her boyfriend of three years, Zhao Mingkai, on the day of her father's sixtieth birthday. Unexpectedly, Zhao Mingkai temporarily brings along junior sister Tang Yuwei, who not only takes Xiaoning's seat but also repeatedly ignores the feelings of her girlfriend and family at the birthday banquet. As cooperation projects, family banquet photos, and engagement plans are affected one after another, Cheng Xiaoning gradually realizes that the concession in this relationship has long lost its balance.