A local hazard mitigation plan (LHMP) or emergency plan is one of the most effective contributions for the mitigation of future local natural disasters. Since different regions are vulnerable to different natural disasters, each community should prepare their own plan based on their specific conditions. In Kumamoto, chronic flood damage and landslides are the most common hazards. In 2012, rapid heavy rain resulted in substantial property damage, casualties, and even fatalities. Studies indicate that Japanese communities have many volunteer groups to manage natural hazards and that their average risk reception is higher than in any other country. It can be said that Japanese government policy regarding natural disasters is good. However, it is time to reconsider our approach and reconfirm our fundamental commitment of designing an LHMP. This paper presents comparison research for Kumamoto hazard mitigation planning around 10- year time series, a longitudinal study. We used a flood mitigation plan coding protocol to better understand the Kumamoto City hazard mitigation plan. Indicators used in the study mostly focus on situations that the city has recently faced. Ultimately, the purpose of this research is twofold: 1) to assess the current mitigation efforts for a local flood event through a comparison study, and 2) to improve the LHMP more practically. To increase credibility and reliability, each researcher in this project checked the LHMPs three times. Eventually, through this study, it should be possible to enable the local government of Kumamoto to help establish a community resilient to its chronic natural disasters. Specific goals include determining which parts in the LHMP should be reinforced and whether improving the community resilience to flooding is possible