In "Death Note," the battle between righteousness and self-interest is depicted through the conflict between the protagonist, Light Yagami, and the antagonist, L. Light initially believes that he is using the Death Note for a righteous cause, to rid the world of criminals and create a utopia. However, as the series progresses, it becomes clear that Light's actions are driven more by his own self-interest and desire for power rather than a true sense of justice. On the other hand, L represents the pursuit of justice and righteousness, as he is dedicated to catching Kira (Light's alter ego) and bringing him to justice, even at great personal cost. Ultimately, the series explores the moral complexities and consequences of pursuing one's own self-interest at the expense of righteousness.