The book showcases the work of eight leading researchers and covers a wide range of topics, including computer vision, assistive user interfaces for people with disabilities, AI robotics, multi-agent systems, social behavior analysis, personality prediction, artificial consciousness, symbol grounding, and consensus-building technologies. It also explores fundamental aspects of human cognition and behavior, including autism spectrum disorder, latent human traits, stress, and mechanisms underlying social interaction. Through both theoretical insights and real-world applications, the book highlights innovative technologies that deepen our understanding of humans while advancing intelligent systems designed to collaborate with them. Together, these contributions offer a comprehensive view of the future of human-centered AI and symbiotic human-machine systems.This book provides researchers and practitioners in HCI, AI, cognitive science, and related fields with valuable insights into emerging developments and encourages deeper reflection on the evolving relationship between humans and information technology.This book is based on the CREST research program in Japan.