From "One Piece" and "Naruto" to "Doraemon" and "Sazae-san," comic books have been the heart of Japanese pop culture.
Most "anime," "cosplay" and other made-in-Japan examples of "otaku" ("nerd") culture that have spread worldwide would not exist without "manga" because few anime producers are willing to invest the time and money on stories that aren't proven popular in comic books first.
In the eyes of many Westerners, adults reading manga on a train or at a convenience store appear peculiar, at best.