  Manga, Japanese comics, has been popular on a global scale. Social networks
among characters, which are often called character networks, may be a
significant contributor to their popularity. We collected data from 162 popular
manga that span over 70 years and analyzed their character networks. First, we
found that many of static and temporal properties of the character networks are
similar to those of real human social networks. Second, the character networks
of most manga are protagonist-centered such that a single protagonist interacts
with the majority of other characters. Third, the character networks for manga
mainly targeting boys have shifted to denser and less protagonist-centered
networks and with fewer characters over decades. Manga mainly targeting girls
showed the opposite trend except for the downward trend in the number of
characters. The present study, which relies on manga data sampled on an
unprecedented scale, paves the way for further population studies of character
networks and other aspects of comics.
