Suda51 drew influence from film noir, particularly the theme of multiple personality disorder, and called "Killer7" a "hardboiled action-adventure". Hiro Sugiyama, Peter Saville, and American comic book artists, such as Adrian Tomine, inspired the artistic design and aesthetic. Suda51 noted the inclusion of cel animation in Western and Japanese anime styles was meant to legitimize video games as an art form by competing with traditional art forms in their stage. The game's anime sequences were created by Xebec, while the CGI sequences were handled by Digital Frontier. Kobayashi commented that "Killer7" is "styled more as an interactive story than a traditional game." Suda also drew from yakuza film "". His experience as an undertaker had a powerful effect on the portrayal of death in his games. The game reflects his interest in professional wrestling; Suda51 included a luchador character, Mask de Smith, and conducted interviews and attended promotional events while wearing a lucha libre mask. Reflecting on his work, Suda51 considers "Killer7" his proudest achievement.