This study revisits The Red Book, the foundational but long-overlookedresearch document that guided the conception of Festival Plaza for Japan'sExpo '70. Conceived by Arata Isozaki and collaborators under Kenzo Tange'slaboratory, The Red Book envisioned a technologically responsive "managedplaza" -- a new urban typology merging architecture, performance, andtechnology into an interactive system. Integrating robotics, computercontrol, and feedback mechanisms, it proposed a space shaped by humanparticipation, linking Japanese festival (matsuri) traditions to cyberneticexperimentation and the cultural renewal of public space in postwar Japan. Though many ideas remained unrealized,The Red Book embodied a radicalsynthesis of architecture, media, and social theory, revealing a collaborativemodel of design that anticipated later concepts of responsive environments.Its ongoing relevance lies in its speculative approach to technology and civicspace. As both research document and design manifesto, it exposes tensionsbetween control and freedom, spectacle and participation. The translationand critical study of The Red Book illuminate how Expo '70's visionaryambitions prefigured current debates on interactivity, governance, and therelationship between architecture, society, and information systems.