Japan is known for its frequent natural disasters such as floods and earthquakes, and various regions of Japan have been affected by large flooding even in recent years. Long-term high-resolution gridded precipitation datasets have been frequently utilized to understand the characteristics of various floods. Here, we introduce our newly developed 0.01-degree gridded precipitation data for Japan covering 1926 to 2020 (Hatono et al., Scientifc Data, 2022). We compiled various precipitation observation data from over 1,000 stations and applied a simple spatial interpolation method. Cross-validation analysis showed that over half of the validated stations showed an NSE of over 0.6 in each year. Preliminary investigations showed large differences in the precipitation characteristics of main channel and tributaries of Nuta River in Hiroshima prefecture when considering precipitation in the upstream area. We expect our dataset to be applied to various precipitation-related research, and to contribute to understanding the spatiotemporal characteristics of floods throughout Japan.