In this world, people develop sub-genders that affect their reproductive organs and pheromonal attraction during their teenage years, and Luo Zhi Yu and Xiao Yan are no exception. The two have been at odds since they were three years old, constantly bickering and getting on each other's nerves. However, during a fight, they both end up developing their sub-genders at the same time: Xiao Yan as an alpha, and Zhi Yu as an omega. Despite the fact that alpha and omega sub-genders are usually drawn to each other, Xiao Yan and Zhi Yu end up medically testing to have 0% compatibility. But everything changes when Xiao Yan suddenly gives Zhi Yu a mating bite – and says that they should get married.