Ohba has no visual preferences and therefore let Obata create the visual aspects. Obata based Mikami's design on Taro Kagami, the main character in the pilot chapter of the series. He was told that Mikami was supposed to be a "stoic character like Light" while not knowing that Mikami was a prosecutor and a follower of Kira. As the series progressed, Obata drew Mikami as an "insane fanatic." Obata said that he gave Mikami glasses since "glasses are in these days." Obata added that "things were a little haphazard at this point..."