The story is the beginning and journey of a new chapter in Choi Mira's life after graduation. In her hectic journey to fulfill her life dreams, she will experience sweet moments but also sad moments. Becoming a full time caretaker of a new nursery is not an easy task as she struggles in taking care of children, and following what her heart yearns for. As the only girl in a family with three older brothers and one younger brother, she was most doted on by the whole family. Even her youngest, Hansol a.k.a. Vernon is overprotective of her because of her tiny appearance while infact her height is above average and she also knows taekwondo. But even so, this does not stop her 4 brothers from being super protective over her as they grow up.

Now, Mira is a graduate and is determined to open her own nursery because it has always been her dream since she was in high school and that she just adores kids in general. The appearance of 12 handsome men and their bundle of joys is just a calm before the storm.