Shinji Watanabe is a professor in the Department of Basic Sciences at the Kyushu Institute of Technology. He received his Doctor of Science from Tohoku University in 2000. He was a post-doctoral research fellow at Osaka University, a research associate at the Institute for Solid-State Physics (ISSP) of The University of Tokyo and at the School of Engineering of The University of Tokyo, and an associate professor in the Department of Materials Physics at Osaka University and in the Department of Basic Sciences at the Kyushu Institute of Technology. He has served in his current position since 2021. His work is concerned with strongly correlated electrons and quantum many-body problems.Kazumasa Miyake is an invited professor in the Graduate School of Science at Osaka University. He received his Doctor of Science from Nagoya University in 1979. He was an assistant and associate professor at Nagoya University in 1976–1987 and 1987–1991, respectively, and an associate professor and professor at Osaka University in 1991–1994 and 1994–2013, respectively. After his retirement in 2013, he was a fellow at the Toyota Physical and Chemical Research Institute until 2017 and has been an invited professor at Osaka University since 2017. His work is concerned with condensed matter theory, particularly superconductivity and magnetism in strongly correlated electrons.

• Prologue.- Early History of Critical Valence Fluctuations.- Fundamentals of Heavy Fermion State.- Anomalous Phenomena due to Critical Valence Transition.- Self-Consistent Renormalization Theory.- Quantum Criticality of Valence Transition -Experiments and Theory.- Interplay between magnetic QCP and valence QCP.- Instead of Epilogue – Ubiquity of Critical Valence Fluctuations.

Shinji Watanabe is a professor in the Department of Basic Sciences at the Kyushu Institute of Technology. He received his Doctor of Science from Tohoku University in 2000. He was a post-doctoral research fellow at Osaka University, a research associate at the Institute for Solid-State Physics (ISSP) of The University of Tokyo and at the School of Engineering of The University of Tokyo, and an associate professor in the Department of Materials Physics at Osaka University and in the Department of Basic Sciences at the Kyushu Institute of Technology. He has served in his current position since 2021. His work is concerned with strongly correlated electrons and quantum many-body problems.Kazumasa Miyake is an invited professor in the Graduate School of Science at Osaka University. He received his Doctor of Science from Nagoya University in 1979. He was an assistant and associate professor at Nagoya University in 1976–1987 and 1987–1991, respectively, and an associate professor and professor at Osaka University in 1991–1994 and 1994–2013, respectively. After his retirement in 2013, he was a fellow at the Toyota Physical and Chemical Research Institute until 2017 and has been an invited professor at Osaka University since 2017. His work is concerned with condensed matter theory, particularly superconductivity and magnetism in strongly correlated electrons.

• Prologue.- Early History of Critical Valence Fluctuations.- Fundamentals of Heavy Fermion State.- Anomalous Phenomena due to Critical Valence Transition.- Self-Consistent Renormalization Theory.- Quantum Criticality of Valence Transition -Experiments and Theory.- Interplay between magnetic QCP and valence QCP.- Instead of Epilogue – Ubiquity of Critical Valence Fluctuations.

Shinji Watanabe is a professor in the Department of Basic Sciences at the Kyushu Institute of Technology. He received his Doctor of Science from Tohoku University in 2000. He was a post-doctoral research fellow at Osaka University, a research associate at the Institute for Solid-State Physics (ISSP) of The University of Tokyo and at the School of Engineering of The University of Tokyo, and an associate professor in the Department of Materials Physics at Osaka University and in the Department of Basic Sciences at the Kyushu Institute of Technology. He has served in his current position since 2021. His work is concerned with strongly correlated electrons and quantum many-body problems.Kazumasa Miyake is an invited professor in the Graduate School of Science at Osaka University. He received his Doctor of Science from Nagoya University in 1979. He was an assistant and associate professor at Nagoya University in 1976–1987 and 1987–1991, respectively, and an associate professor and professor at Osaka University in 1991–1994 and 1994–2013, respectively. After his retirement in 2013, he was a fellow at the Toyota Physical and Chemical Research Institute until 2017 and has been an invited professor at Osaka University since 2017. His work is concerned with condensed matter theory, particularly superconductivity and magnetism in strongly correlated electrons.

• Prologue.- Early History of Critical Valence Fluctuations.- Fundamentals of Heavy Fermion State.- Anomalous Phenomena due to Critical Valence Transition.- Self-Consistent Renormalization Theory.- Quantum Criticality of Valence Transition -Experiments and Theory.- Interplay between magnetic QCP and valence QCP.- Instead of Epilogue – Ubiquity of Critical Valence Fluctuations.