O'Malley wanted to write a shōnen-style comic book series, although he had only read one such series at the time, Ranma 1/2; in the early 2000s, Japanese manga had not yet achieved significant popularity in North America. O'Malley gained inspiration from the book Even a Monkey Can Draw Manga by Koji Aihara and Kentaro Takekuma. In 2002, O'Malley's roommate, who worked in a comic book store, brought the book to him while O'Malley was working on Lost at Sea and was planning Scott Pilgrim. Upon reading the book O'Malley realized that, despite the satirical tone, it could be an effective guide to how the Japanese comic book industry worked. O'Malley said that Ranma 1/2 was the strongest influence and Atsuko Nakajima, the character designer of the Ranma 1/2 anime and other anime, was an influence to a lesser extent. He added that the "exploded page layouts" of Koudelka, a work by Yuji Iwahara, directly influenced the "full-bleed layouts" of Scott Pilgrim. O'Malley said that Osamu Tezuka began influencing his work as he created Volumes 3 and 4. He said, "You can see his influence start to creep in here and there but he’s a larger inspirational figure to me than just his drawing style. " In regards to the FLCL anime, O'Malley said that while it was an influence, it was "not as much of a direct influence on Scott Pilgrim as people seem to think. "