Maybe you could get a recommendation from your hotel for a robatayaki (Japanese barbeque) place that offered the usual grilled chicken for your wife, but had sashimi (somewhat unusual, but not unheard of) for you. More likely you'd get your fish grilled, though.

Also, depending on your interest, you may want to look for "What's What in Japanese Restaurants," by Robb Satterwhite, ISBN 4770020864