This study revisits The Red Book, the foundational but long-overlooked research document that guided the conception of Festival Plaza for Japan’s Expo ’70.

Conceived by Arata Isozaki and collaborators under Kenzo Tange’s laboratory, The Red Book envisioned a technologically responsive “managed plaza” — a new urban typology merging architecture, performance, and technology into an interactive system. Integrating robotics, computer control, and feedback mechanisms, it proposed a space shaped by human participation, linking Japanese festival (matsuri) traditions to cybernetic experimentation and the cultural renewal of public space in postwar Japan.

Though many ideas remained unrealized,The Red Book embodied a radical synthesis of architecture, media, and social theory, revealing a collaborative model of design that anticipated later concepts of responsive environments. Its ongoing relevance lies in its speculative approach to technology and civic space. As both research document and design manifesto, it exposes tensions between control and freedom, spectacle and participation. The translation and critical study of The Red Book illuminate how Expo ’70’s visionary ambitions prefigured current debates on interactivity, governance, and the relationship between architecture, society, and information systems.