How to Make It
In a bowl, combine the shoyu with the rice vinegar and sesame oil. Using a vegetable peeler, remove strips of skin from the cucumbers. Halve the cucumbers lengthwise and cut crosswise into 1/2-inch half moons. Add the cucumbers and scallions to the bowl, season with pepper and toss to coat. Refrigerate for 15 minutes. Sprinkle with the bonito flakes and serve.
Shoyu is less salty than Chinese soy sauce. Both shoyu and bonito flakes are available at Asian specialty-food stores.