 Most of the other characters are based on memories of former high-school classmates; As a manga author, Kobayashi also designed the cover art.Originally, the fifth volume's front cover was to feature Akira Takano, but after re-reading the volume Kobayashi concluded that since much of its plot in that volume revolves around Karen Ichijo, she should be on the cover instead.Desiring to feature a male character, he placed Harima on the cover of volume six.