Naomi Misora was a former FBI agent and the fiance of Raye Penber. During her time as a FBI agent, Naomi worked under L.

After the death of her fiance, Naomi was understandably distraught. She decided to find Kira no matter what. She managed to figure out that Kira could kill in ways other than a heart attack. In her attempts to contact L with this information, she met Light. After gaining her trust, he managed to get her to show an ID, after which he used the Death Note to cause her to commit suicide in a way that would not allow her to be found.