Naomi's character was originally intended to have a larger role in the storyline which included investigating possible suspects for the Kira Case and expanded interaction with her fiancé. However, once Raye's character was killed author Tsugumi Ohba believed that having Naomi search for Kira was a "natural and interesting development" in the story. Within the cast of characters at the time Sayu was the only notable female. In adding Naomi, Ohba could finally have the "cool" female character he had always wanted. He initially planned for Naomi to have a long involvement in the story but underestimated the character's deductive abilities. Because she was able to uncover crucial plot information "faster than... thought", Ohba decided to end her character early to avoid facing complications with the story development later on. He described the storyline issue of Naomi as the greatest difficulty that he created for himself since the beginning of the series.