Misa Amane is a fictional character who appears in the narrative of L: Change the WorLd, a story set within the Death Note universe. She is a famous model, actress, and pop idol known by the nickname Misa Misa. Born in Kyoto on December 25, her early life is marked by tragedy: a burglar murdered her parents in front of her, and the legal system failed to deliver the justice she sought. When the vigilante Kira killed that burglar, Misa became a devoted supporter of Kira, viewing him as a savior. She later inherits a Death Note from the shinigami Rem, originally owned by the shinigami Gelus, who died to save her life. With this notebook, Misa takes on the role of the Second Kira, using it to kill criminals in support of Kira's mission. To aid her cause, she makes a deal with Rem, trading half of her remaining lifespan for the Shinigami Eyes, which allow her to see any person's name and lifespan just by looking at their face. She repeats this exchange later with the shinigami Ryuk, further shortening her life.

In L: Change the WorLd, Misa is portrayed as an even more prominent celebrity, working as a singer, and L's obsession with her becomes notably greater than in the main series. Her personality is outwardly bubbly, hyperactive, and childlike, often referring to herself in the third person as Misa Misa. Beneath this cheerful exterior lies a deeply disturbed and morally compromised individual who is willing to kill without hesitation if it serves her goals. Her primary motivation is her overwhelming, one-sided love for Light Yagami, the human identity of Kira. She devotes herself entirely to him, accepting his manipulation and using her celebrity status, charm, and Death Note abilities to further his plans, even when he treats her coldly. Her relationship with Light is exploitative; he sees her as a useful tool due to her Shinigami Eyes and public influence, while she remains blindly loyal. She also forms a protective bond with the shinigami Rem, who cares for her well-being, and she is a suspect in L's investigation, leading to confrontations that test her resolve. Over the course of the story, Misa's devotion deepens despite the emotional toll, and after Light's eventual death, she descends into despair. In the extended canon of the manga and databooks, she commits suicide on Valentine's Day, roughly one year after losing him. Her notable abilities include the use of her Death Note, the Shinigami Eyes (which she applies with quick, often reckless judgment), and her social influence as a pop idol, which she wields to manipulate public opinion and gather information. Despite her apparent frivolity, she demonstrates cunning and a willingness to sacrifice herself, making her a tragic figure caught between genuine love and destructive obsession.