Despite the high-level prevention measures against natural disasters in Japan, the Mw 9.0 2011 Tohoku earthquake and the subsequent tsunami caused a lot of damages and fatalities along the east-northeast coast of Honshu Island. For prior study on applying the Integrated Tsunami Intensity Scale (ITIS2012) in the broader Ishinomaki area, a series of information on the multi-level preventive measures and their effectiveness has been collected. This study aims to identify the influence of these measures and to extract exploitable conclusions. The multi-level approach of the ITIS2012 revealed countermeasures on: citizens training and awareness, urban planning and infrastructure protection. Data have been collected from official reports, satellite imagery, the literature and published information and mapped along with the damages. Effectiveness degree of these measures, but also failures, incorrect implementation or inadequacies have been identified, analyzed and classified. Prevention and protection measures reduced damage and losses: Early Warning System, annual citizens training, tsunami hazard planning, evacuation shelters, seawalls, breakwaters, coastal forests and strict earthquake-resistance legislation seem to be effective. However the hazard had been underestimated by citizens and the authorities; limited training participation has been recorded; shelters, port facilities and seaside wooden structures have been destroyed; the seaside industrial has been source of further disasters. Tohoku mega-tsunami revealed some exemplary protection and prevention measures and measures that require further study on their adequacy and applicability. Extracted conclusions and proposals would be particularly useful to Authorities in countries facing the hazard of the same natural phenomena.