We applied a real-time tsunami inundation forecast system to a disaster response plan. We developed a standard operating procedure (SOP) for a tsunami disaster response based on a Plan, Do, Check, Action cycle to effectively use tsunami observation and prediction information provided by a real-time tsunami inundation forecast system during an initial response to a tsunami disaster. In the Plan stage, we ran a workshop on the tsunami disaster response to confirm the current tsunami disaster response plan and develop a timeline plan for a tsunami disaster. In the Do stage, we conducted a tabletop exercise (TTX) for a tsunami disaster using a real-time tsunami prediction system. In the Check stage, we ran a workshop on an after-action review of the TTX. In the Action stage, we applied the SOPs of the real-time tsunami prediction system to the tsunami disaster management plan and conducted a second TTX. As a result, we verified the information provided by a real-time tsunami prediction system to apply the system to a tsunami disaster management plan for real municipalities. It was confirmed that the SOP that we developed allows a real-time tsunami inundation forecast system to enable government staff to safely and effectively respond during a disaster.