A magnitude 9.0 earthquake struck off northeastern Japan on 11 March 2011. The subsequent tsunami wrought destruction on a massive scale. Kesennuma City was one of the most heavily damaged regions in Miyagi Prefecture, where more than 1000 people were killed by the tsunami and resulting fire; 215 people are still missing. Here we analyzed historical landuse changes in the tsunami-affected area of Kesennuma city center, Miyagi Prefecture, using topographic maps from 1913 and 1952 and vegetation maps from 1979 and 2011. The area consisted of 7.3% urban land use, 10.5% dry field, 55.5% rice paddy field, 4.7% wetland, 0.3% grassland, 5.3% forest, and 16.3% water body in 1913 and 76.1% urban land use, 1.7% dry field, 17.9% rice paddy field, 0.9% wetland, 1.6% forest, and 1.6% water body in 2011. During the period, the area of urban land use increased more than 10-fold, while that of rice paddy field sharply decreased from 55.5% to 17.9%. The 77 Bank estimated that the total economic damage in Kesennuma City was 232.4 billion yen, representing annual production value of all companies located in the damaged area. Our calculations for urban land use, dry field, and rice paddy field showed losses of 112.7 billion yen and 69 million yen due to the tsunami in the areas of urban and agricultural land use, respectively.