The song is a prequel to Eminem's 1999 track "'97 Bonnie & Clyde
," where he raps about throwing Kim's body in the trunk and dumping it in a lake. "Kim" depicts what led to this point, how they got into an argument and he killed her.
It's pretty shocking stuff, especially since Eminem used the real names of his wife and daughter in the song. And while no rational person believes he wanted to kill her in real life, their relationship was fraught with turmoil. The buffer here is Eminem's character Slim Shady, who expresses his base impulses. Much of Em's early work depicts a battle between his true self (Marshall Mathers), and the volatile Shady, who he can't always control. His fans got it, but many listeners didn't and found the song misogynist and offensive. The ensuing controversy got him in the news even more, especially when he and Kim divorced, and helped sell a lot more albums.