In Death Note, the pursuit of justice is depicted as a central theme through the protagonist Light Yagami, who uses the Death Note to eliminate criminals and create a world free of evil. However, as Light's pursuit of justice becomes more extreme, he starts to rationalize unethical and immoral actions in the name of achieving his vision of a just society. This ultimately leads to a moral ambiguity where the lines between right and wrong become blurred, showcasing the consequences of pursuing justice at any cost.