Since the ’90s successes of Mariko Mori’s flawless digital fantasies of technofemininity and Takashi Murakami’s anime-derived subjects, the Japanese art most widely exhibited abroad has conformed to two easily generalized types: high-tech and neo-Pop. Carefully weighted against the expectations produced by this export history, “Mediarena: Contemporary Art from Japan,” a survey of current practice from the Kanto and Kansai regions (centered on Tokyo and Osaka), energetically displayed a more complex spectrum of media and artistic modes, partly by locating recent work in a lineage of action-based