Paranoia Agent (2004 - 2004)

The anime series "Mousou Dairinin" is about a troubled teenage criminal who has lost his mind. A mysterious high school student appears in various locations in the metropolis, wielding a baseball bat and unexpectedly attacking unrelated people. One of his random victims turns out to be the designer Tsukiko Sagi, who created the popular animated character Maromi. Two detectives take on the case and suspect that the boy's personal vendetta is somehow connected to that very fictional character.