"A sparrow who yearns to live a long life aims to capture a human to fulfill her goal... through marriage?!"

In a world where wildlife birds are able to permanently turn into humans once they seal a marriage contract with a human, Jo Ahyoung enters university with the goal of finding her potential marriage partner to live a longer life. Rather than hoping for a romantic meeting, she makes up her mind to take any human that can provide her with a stable and secure living. But is that as easy as she thinks it to be...?