When I make nikumaki, I make a salad dressing/dipping sauce of mayonnaise, soy sauce, rice wine vinegar, and mirin. I never seem to remember to put sesame oil in, but that’s OK. It tastes good as it is. We use it on the Spring-greens salad as a dressing, and as a dipping sauce for the nikumaki.
Does this dressing have a Japanese name?