Han Hae Na is a single secondary school teacher with a family secret. Because of an ancestor, Han Hae Na’s family has been cursed for generations. Whenever a member of her family kisses someone, at midnight they turn into a dog for six hours. Afterwards, they return to their normal appearance. This transformation repeats itself every night until that person, in their dog form, kisses the same person. Whenever Han Hae Na meets a man with a view to a potential romantic relationship, she asks him not to kiss her. This usually leads to the men breaking up with her. One evening, whilst drunk, Han Hae Na accidentally kisses Jin Seo Won, a teacher at the same secondary school, even though they aren’t even particularly close as colleagues. Han Hae Na immediately panics and persistently approaches Seo Won in the hope of another kiss. However, Jin Seo Won is afraid of dogs.