Tao had a beautiful love story with his ex girlfriend, Park Taeri. Tao didn't know that she is a vampire. Taeri turned Baekhyun into a vampire but he didn't know that. A year later, Taeri turned Tao into a vampire and that is where Baekhyun found out that he is a vampire too. Tao turned the rest of his brothers into vampires as well because he needed blood. The Kim twins didn't know that they're vampires.