While the tsunami-induced wave forces have often been calculated using hydrostatic pressure relation and correction coefficients, few studies have targeted on the tsunami forces acting on head and corner sections of breakwaters. In this study, on the basis of hydraulic model experiments and numerical simulations, we investigated the correction factors for estimating the tsunami force, characteristics of water-level distribution, and its reproducibility by numerical model around the corner and head sections of breakwater under tsunami-overflow conditions. The hydraulic model experiment demonstrated that the correction factor measured in front of (behind) the corner of breakwater was ~1.0 to 1.1 ( ~0.9 to 1.0) and less than 1.0 in front of the head. This indicates that the wave-pressure can be estimated to a safe side if the conventional correction coefficients are used. It was also found that the waves can be concentrated locally under conditions of shorter-period tsunami’s overflow. Numerical experiments using CADMAS-SURF/3D and nonlinear long-wave numerical model reproduced the water-level distribution well and to a safe side, respectively.