A promise. 

As they grew up, Jihan and Minjae would get married, despite being an atypical couple in a society where omegas were supposed to mate with alphas—and betas were considered inferior. 

But the two childhood friends persisted in their love, ignoring the disdain of others. 

Now, Jihan feels cold and wrong, and although he still loves Minjae, he can't connect with him—or at least touch him intimately, leaving Minjae hurt. 

Amidst the tension emerges Yoon Seungmin — the alpha heir of the Yoon House — known for being a libertine, who is determined to take the omega to bed and mocking Jihan, since a beta could never satisfy an omega. 

Meanwhile, King Kim Seom of Dalseong falls ill, and Jihan's secret comes to light.