For Alpha Doctor Han, life is meant to be orderly and precise―at least, until it comes to his daughter, Haeun. Clever, charming, and impossibly stubborn, she's the little trouble who can turn his carefully managed world upside down in an instant. Even those who love her admit she's a handful... and no one has managed to keep up with her for long. Somewhere else in the city, Omega Jay a.k.a Hwang Byeol faces a storm of his own. With tension rising inside his gang and enemies closing in, he's forced to disappear for a while. His escape takes an unexpected turn when he comes to help him and became a babysitter―a role that will let him lay low and keep his face out of trouble. Under the name Yence, he steps into a new life that's far quieter... and far more complicated than he planned. As Haeun's spirited nature meets someone who can finally match her pace, Han begins to wonder: is this newfound peace just what his daughter needs, or is it the calm before a storm? And when trouble finally knocks, will the Alpha be ready to face it―or will his little trouble lead him straight into it?

After AHOF's First Spark concert in Manila, Park Han begins noticing something he wishes he never had. Every night, JL disappears into Steven's room. Every morning, they laugh like nothing happened. No one else thinks it's strange. So Han tells himself not to care. After all, JL isn't his. But the more he tries to ignore it, the more it consumes him. Every smile JL gives Steven feels like another reminder that Han has already lost-without ever having a chance to begin. So Han buries his feelings... until they finally break him.