Wonwoo lives alone with his puppy in a two bedroom apartment just a few blocks away from his work. When he brings home a stray injured black cat his puppy senses something strange about the cat. Soon Wonwoo finds out that the cat is no ordinary cat; it's a hybrid. Mingyu is the only Hybrid in Seoul as far as Wonwoo knows. Wonwoo has difficulty trying to keep Mingyu being a cat a secret which of course is hard due to the ears and tail.