Tokyo's downtown Sumida Ward, which is under threat from inland flooding, has been forced to give up on installing rainwater infiltration facilities due to high groundwater levels. However, this area was once a farming village, and rain was stored in the rice fields, nurturing plants and animals, and rainwater was considered a “blessing”. Therefore, I focused on historical agricultural environments where water was controlled artificially while maintaining harmony with the natural environment, and proposed a rain garden that applied the horizontal penetration phenomenon called “ridge penetration” in the ridges of rice fields. This is an attempt to create a beautiful landscape where rainwater circulates by weaving the rural context of the past into the modern urban environment.