It certainly sounds promising.
One thing with a lot of people (any gender) is, we need it to be kind of hammered into our skulls to learn someone likes us. You need not put it in sky writing, but there is nothing wrong with contacting him and saying, "You know, I have such a great time getting sushi. Would you like to get Italian? And maybe make it a real date this time?"
If he did not mean it as a date, then he has an out; he can apologize and say he was just doing the friend thing. If that is the case, be gracious and let him off the hook.
If he did mean it as a date, then he will more than likely be thrilled that you feel the same, and that you have given him a clear signal of interest.