You soak each foot in water before going out in the sun to take your first step. Stepping on the ground when it's been baking in the hot sun can burn your feet, so you're careful to make them wet with water before stepping outside even once.
Each step you take brings you closer to とうきょう. Unfortunately, the sun keeps getting hotter, meaning you have to take breaks between steps more often, to get your feet wet with even more water. But you're determined to reach とうきょう, no matter how many steps it takes.