This study aims to reexamine the historical perceptions of the Japanese comic book medium, particularly the "magazine culture" which began in the late I960s, by tracing the historical process of creating "Shinshoban comics" during the 1960s and 1970s. Prior historical studies of postwar manga have not fully examined manga comic magazines, and manga has usually been defined as one type of comic magazine, not as its own independent form of media. Accordingly, in this article, I focus on the "Shinshoban comics" that predated present-day manga comics in order to understand the transformations in the comic industry during the late 1960s and early 1970s. Unlike the manga comics of today, due to the lack of modern industry and marketing systems, Shinshoban comics were very marginalized and crossed over various manga publishing borders. However, as series of Shinshoban comics based on particular comic magazines became the dominant publication style of manga comics, they were gradually perceived to be one type of comic magazine in the comic industry. Moreover, in the political and cultural climate of that time, the publication of some Shinshoban comics was delayed while others were screened out. Some of the works filtered out of the major public companies were published by small publishers as well as Kashihon publishers, which published for book-lending shops. As a result, though Shinshoban comics were subsumed by the comic publishing industry as a part of magazine culture, they were also relatively independent and established themselves as an original publishing medium. Therefore, an investigation of the historical process of creating Shinshoban comics clarifies that the industrialization centering around comic magazines produced by the major publishers beginning in the late 1960s contained within it a complexity that gave rise to an "independent" or "derivative" media culture.