Light Yagami's relationships with those who oppose him in the anime "Death Note" are significant as they serve to highlight his complex character development and moral descent. His interactions with L, Near, and other opponents provide insight into his intelligence, cunning nature, and willingness to do whatever it takes to achieve his goals. These relationships also demonstrate the psychological cat-and-mouse game that unfolds throughout the series, showcasing the intensity of the battle of wits between Light and his adversaries. Additionally, the contrast between Light's charisma and manipulative tendencies and the integrity of his opponents adds depth to the narrative and raises thought-provoking questions about justice, power, and the nature of good and evil.