The manipulation of circumstances plays a crucial role in Light Yagami's plans in the anime "Death Note." By strategically manipulating events and people around him, Light is able to further his goals of creating a world free of crime and becoming the god-like figure known as Kira. Light uses manipulation as a tool to outsmart his opponents, control situations to his advantage, and eliminate anyone who stands in his way. This manipulation of circumstances showcases Light's intelligence, cunning nature, and his willingness to do whatever it takes to achieve his objectives.