In a medium mixing bowl, combine sliced cucumbers and salt. Stir until well combined and then cover. Set aside for 10 minutes.
Combine the rice vinegar, mirin, sugar, and soy sauce in a small mixing bowl. Stir until combined.
Using your hands or a cheesecloth, squeeze the liquid out of the cucumbers. Once the cucumbers have been squeezed out, transfer them to a new bowl.
Pour the dressing over the cucumbers and stir until well combined. Cover and let sit for 1-2 hours before serving.
Serve topped with sesame seeds for garnish.
