High school Korean literature teacher Han Hae-na suffers from an extremely unusual curse: If she kisses a man, she is doomed to turn into a dog every night, although she returns to human form in the morning. There is only one way to break the curse – and that involves receiving a kiss from the same man who kissed her...while in dog form! She has a crush on Lee Bo-gyeom, a colleague who teaches history at the same school. She is smitten with him, even claiming that he is the sole reason she wants to keep coming to work every morning. But she forgets herself one night, and drunkenly kisses him – only to discover that it wasn’t Lee Bo-gyeom after all...but actually Jin Seo-won, another male colleague. Unfortunately, although Jin Seo-won is extremely handsome, he is also terrified of dogs due to a traumatic event in his past. He also has a natural aversion to her. Now Han Hae-na must find a way to win his heart – and get him to kiss her – or spend the rest of her life as a pooch!