While cucumber and tomatoes are marinating, make the dressing by combining rice vinegar, soy sauce, sugar, garlic, sesame oil, chili oil, and pinch of salt together. Set aside.
3 tablespoon rice vinegar, 2 tablespoon soy sauce, 1 tablespoon granulated sugar, 3 cloves garlic, 2 teaspoon sesame oil, 1 tablespoon chili oil, Pinch of salt