Light Yagami, the protagonist in the anime "Death Note," manipulates the legal system by using the Death Note, a supernatural notebook that allows him to kill anyone whose name he writes in it. By targeting individuals involved in law enforcement, government, and the justice system, Light is able to eliminate obstacles and shape the legal landscape to his advantage. Additionally, he strategically plans his actions to ensure that his killings appear as natural deaths or accidents, avoiding suspicion and further manipulation of the system.