Geological investigations of tsunami deposits have proliferated since the 2011 Tohoku-oki tsunami in Japan, and are important in developing tsunami disaster prevention plans. However, studies of tsunami deposits in Japan are localized and do not cover the entire coastal zone. In light of these gaps in knowledge, further detailed studies of tsunami deposits should be encouraged. Most of the existing research needs to be reevaluated and integrated before incorporating the results of these studies into disaster prevention plans. Currently, there is no comprehensive summary of previous research on tsunami deposits and this hinders identification of the best sites to focus new investigations of such deposits in Japan. Here, we summarize previously published papers, books, and reports describing tsunami deposits in Japan, and identify sites that need further geological study. Our review of this literature indicates that existing research has mainly been conducted along the Pacific coast, where the risk of large tsunamis is high. A small number of studies have been carried out in parts of Hokkaido, north of Tohoku, the east coast of Kanto, and Kyushu. Very few studies of tsunami deposits have been carried out along the Japan Sea coast.