Since 2014, Japan has been promoting the “Fundamental Plan for National Resilience,” aimed at minimizing damage from natural disasters and facilitating rapid recovery. Japan has a high risk of rockfalls from earthquakes and volcanic activity, as approximately 70% of its terrain is mountainous, making numerous structures and infrastructure located near slopes vulnerable to damage from rockfalls, posing risks to both human life and infrastructure. Consequently, rockfall mitigation measures, including preventive and protective works to reduce rockfall occurrences and mitigate their impacts, are prioritized within the “Fundamental Plan for National Resilience.“ Furthermore, with recent climate change, the scale and frequency of rockfalls have increased, necessitating enhancements in the overall performance of mitigation measures. One of these protective measures includes the development of high-energy absorption rockfall protection barriers capable of capturing rockfalls with energies exceeding 1000 kJ. These barriers are composed of blocking surfaces and support posts designed to absorb the energy of falling rocks efficiently. Blocking surfaces employ devices that absorb kinetic energy through friction and structures that effectively distribute loads. Support posts, which have reinforced steel rods placed inside steel pipes and filled with concrete, are high-ductility, filled steel pipe columns that absorb the kinetic energy of rockfalls through plastic deformation. This study introduces the current state of rockfall protection technologies in Japan and discusses the performance of the high-energy absorption rockfall protection barriers based on the experimental results.