The introduction starts by recounting the history of this project, from an ignorant first encounter with the traces of expos, through the enthusiastic embrace of the burgeoning academic literature on them, to a puzzling first experience of an expo in real life. It suggests that the existence of expos, and their endurance in Japan, challenges the existing literature, which either mines them to explore other phenomena, or assumes that as exemplars of modern spectacle they can serve as an effective ideological apparatus. Rather, it argues, they might help us refine our understanding of development, spectacle, and their relationship, and of modern Japan. Doing so, however, requires us to be alert to the limits of our sources, however extensive the expo archive, and to craft our accounts to reflect these.