Hi Ashley!
You and your husband are going to LOVE The California Grill!!!! I ate there in December, and it was AMAZING!
I spoke to a Disney Cast Member about your question. For the California Grill, sushi is offered as an appetizer. Unfortunately, an appetizer is not included on the basic Disney Dining Plan. However, an appetizer is available on the Deluxe Disney Dining Plan. If you would like more information on the Disney Dining Plans and what each plan has to offer, click
HERE.
Next to the California Grill, there is a place called The Lounge where you can also order sushi. The Lounge does not take reservations, but this might be a nice place to have some sushi and then enjoy your delicious meal at The California Grill!!
If you have other questions, please let me know!
Have a magical trip, and "See You Real Soon!"