Whisk together vinegar, sugar, and salt in a large bowl.

Slice cucumbers into very thin rounds using a Mandoline or food processor.

Add the cucumbers to the marinade. Let marinate in the refrigerator at a minimum of 41 degrees for one hour.

Remove cucumbers the from refrigerator. If using rice, spoon cucumbers over a 1/4 cup of cooked rice.

Sprinkle with sesame seeds and serve.