In a small saucepan, heat rice wine vinegar, sugar and ½ teaspoon of salt. When sugar is dissolved, turn the heat off and set it aside to cool.
Cut cucumbers lengthwise and remove seeds. Slice them crosswise very thin then put them in a medium bowl. Springle cucumber with ½ teaspoon of salt and set it aside for about 5-10 minutes.
When vinegar mixture is cold, mix it with dash and light soy sauce.
Squeeze salted cucumber to remove any excess water then add it to the vinegar mixture. Sprinkle cucumber with sesame and shichimi and put it in refrigerator to chill and pickle at least 30 minutes to an hour before serving.