Substitution for Rice Wine in Donburi

A member of Japanese Cuisine forum asks: "I am currently on a low carb diet and am on a message board with a lovely Canadian lady currently living in Japan. I posed the idea of making donburi as a low carb dish... a little lighter on the flavor because there would be no rice to balance the meal. One thing I'm having difficulty discovering would be a rice wine replacement, as alcohol of any sort is not permitted on this plan..." Post your suggestions in the forum!