The author reviews comprehensive assessment and mitigation strategies for megathrust earthquakes and tsunamis along the Nankai Trough, incorporating historical data, current research, and forward-looking strategies to enhance earthquake and tsunami preparedness. In the last five years since 2018, the Integrated Research Group for Megathrust Earthquakes along the Nankai Trough leveraged interdisciplinary approaches to model seismic wave propagation, assess tsunami inundation, estimate structural damage, and enhance stakeholder engagement through educational outreach and collaborative workshops. Here, the author focuses on the findings from various disciplines, including the analysis of past seismic events, current monitoring technologies, and future scenario planning. Additionally, the evolution of the understanding of megathrust earthquakes is introduced through detailed case studies, such as the 1662 Hyuga-nada earthquake, providing insights into the seismic and tsunami risks specific to the region. The possibility of recent advancements in understanding the interaction between slow and fast earthquakes is also focused on, which offers promising avenues for mitigating future seismic events. By linking historical data with cutting-edge research, there is a further need to significantly advance the field of earthquake and tsunami disaster science and effectively translate these findings into practical strategies for disaster risk reduction.

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