Light Yagami's relationship with his sister, Sayu Yagami, plays a crucial role in the character development of Light in the series "Death Note." Sayu serves as a point of vulnerability and humanity for Light, as his actions and decisions heavily impact her well-being and safety. His protective instincts towards his sister humanize him and showcase a different side of his personality, highlighting the complexities of his character as he navigates the moral dilemmas presented in the series.
