I was back in Restaurant Muramoto this week and asked my dining campanion if he noticed a smell. He responded that he did so I went back outside, sucked down some diesel fumes to clear my palate, and walked back in. It smells like a Japanese restaurant!
I lived in Japan for four years. I spent the last year in a hotel in Tokyo and consequently ate nearly every meal in Japanese restaurants. That smell in RM is what a small restaurant in Japan smells like. It's the ingredients, the deep fryer and the odors that cooking in an open restaurant puts out into the air. Yes, I've been sushi bars or large Westin style dining rooms that don't smell like that, but anywhere that cooked in a relatively small place, smelled like that.
All countries/cuisines/ingredients have unique aromas. Hong Kong doesn't smell like Bangkok and neither at all like Munich. If it bothers you, and smell is a huge part of taste and the enjoyment of food, don't go. But, personally I'd have trouble giving up the duck/mango/avocado roll and the Asian slaw. There's always takeout.