Using her own Death Note, a notebook that allows its owner to kill anyone simply by knowing their name and face that she received from the Shinigami Rem, Misa does everything she can to aid Light.

This includes shortening her own remaining lifespan by half, twice, in order to receive the eyes of a Shinigami, giving her the ability to learn a person's name just from looking at their face.

In the live-action adaptations, she is portrayed by Erika Toda in the films, by Fuka Yuduki and Sakura Kiryu in the musical, and by Hinako Sano in the television drama.

Ohba, intending to introduce her with the Shinigami Eyes,[1] described Misa as having to be "spontaneous and not too bright" and that he determined her personality from the start.

"[2] Obata, imagining a mix of an "energetic Japanese artist" and a "foreign rock and roll singer", felt "set" with Misa's design after drawing her for the first time.

"[4] Obata revealed that his editor warned him that the scene with Misa in restraints in chapter 33 was on "morally thin ground for a children's magazine," so they placed the title logo over the middle of it.

[5] When the Near and Mello story arc began, and Misa became a top idol, Obata decided to drop the Gothic Lolita style and make her look like "a popular actress."

Death Note 13: How to Read also states that Misa "required a lot of artistic variation" because of her "many expressions" that ranged "from goofy to serious.

[9] Misa moves to Tokyo to meet Kira, a vigilante who uses his Death Note to serially murder criminals to rid the world of evil, as she agrees with his goal.

[11] Using her Death Note, the media, and her Shinigami Eyes – in exchange for half her remaining lifetime, she could see a person's name and lifespan just by looking at their face.

Light agrees to use her Shinigami Eyes and even though he tells her upfront their relationship will only be an act, she believes she can ultimately win his love.

[12] According to Ohba, Light sees Misa as a "bad person" who killed innocent people, so he acts emotionally cold towards her and manipulates her.

Misa loses her memories related to using the Death Note, by relinquishing ownership of it, at Light's orders and retains her love for him.

Additionally, Misa first learns of Light's identity as Kira when Soichiro rescues Sayu who was at the TV station attending a fair.

Her memory of the Death Note is erased, but she retains her obsession with Light, wishing him a happy birthday through a mini-shrine dedicated to him.

Briana Lawrence of Anime News Network felt that even though Misa was an annoying girl clinging to the main character, "In a series full of geniuses it was amazing to see an average person get a hold of the Death Note.

[21] In a review of the anime adaptation, Michelle Yu, from the same website, praised Misa, saying she is physically beautiful and a "good-looking female addition to the screen", while also describing her as a "little diva with some serious issues and a very whiny voice".

[22] In a Salon.com article, Douglas Wolk describes Misa as being drawn in a "Japanese comics of cute, tiny, airhead girls with big eyes" and being a "lot cannier than she pretends to be".

[23] Tom S. Pepirium, a writer at IGN, describes Misa in a review of the Death Note anime episode "Performance" as being the "show's most mysterious character".

Pepirium points out the tone in which the character is written, feeling that her motivation and obsession with Kira are "in league with Death Note's dark sensibilities".

He says that when Misa spouts her deep and fully realized affection for Kira in "her wacky, excited, poodle-like way", the information "loses all impact".

[19] Hannah Grimes of Comic Book Resources wrote, "Back when the show first released, Misa became one of if not the most popularly-designed goth characters in all of anime.