Dry direct-seeding rice cultivation requires less labor than traditional transplanting cultivation, as there is no need for seedling production, the puddling process, and the transfer of seedling trays. In northern Kyushu, a double-cropping area in southern Japan, dry direct-seeding rice cultivation has generally not been adopted due to water leakage and the accompanying weed overgrowth. This situation prompted the authors to devise a water leakage prevention technique that can be rapidly implemented after winter cropping, with the aim of guaranteeing a reliable rice harvest. In this study, we use a vibratory roller to compact the soil, investigate the optimal conditions for effective compaction, and demonstrate the procedures for confirming these conditions on-site. This article provides an overview of the research process used to develop this water leakage prevention technique and an outline of our dry direct-seeding rice cultivation method for double-cropping areas, including weed control during the dry period.