Light (or Raito) Yagami, who one day stumbles across a little note-book. He learns that the notebook is of supernatural origin and the instrument of untold power; with it Light can orchestrate the death of any individual he fancies. Light embarks on a mission to clense the world. At the same time, in response to the bizzare murders of criminals occuring, the world's greatest Detective "L" takes it apon himself to bring the murderer "Kira" to justice.

Thus begins a story of the two men locking wits with each other, engaging in a long-drawn out and much bloodied race to find the other person first. Who represents true Justice?