This review summarizes geological research on the tsunami caused by the 2011 Tohoku Earthquake, with a focus on the sediment dynamics and budget, and relationship between hydraulics and deposit characteristics, in two areas with different settings. The tsunami sedimentation in Hirota Bay, Sanriku Coast, was characterized by offshore transport of beach sediments due to an intensive backwash. Onshore transport of marine sediments was inferred from paleontological data, as well as visual observations and numerical modeling of the tsunami. In contrast, geological evidence, video footage, and numerical modeling suggest that onshore transport of marine sediments was limited in Sendai Bay. These differences are best explained by the topographic and bathymetric settings of these sites, and the properties of the tsunami wave. The field of tsunami sedimentology has been significantly advanced through geological studies of the Tohoku tsunami deposits. Further challenges are identified regarding the application of the Tohoku tsunami deposit research to paleotsunami studies and hazard assessment.