In 2012, Kim appeared in six works in the first half of the year: a romantic fantasy television series, Padam Padam; a historical comedy film, I Am the King; a fantasy-period drama Moon Embracing the Sun, in which she gained recognition as the younger version of the second female lead, Kim received commend from the audience and the director of how well she portrayed the antagonist's desire realistically the drama came to rank number one in its time slot throughout its run and achieved a peak recorded viewer rating of 42.2%, thereby earning the "national drama" status Kim simultaneously became "Korea's little sister"; followed by a fantasy-comedy Rooftop Prince in the role as an evil sister; Love Again and a high school student whose roommate is a female idol star in Ma Boy.