There's lots of good restaurants as well all over the place and even at the top floor of many Yodabashi (a giant electronics chain). Don't be afraid of places that don't have any English signage, you can usually request an English menu or see if they can just recommend you a good dish if you're adventurous.
If you're hopping onboard the Shinkansen (bullet train), grab yourself an ekiben at the station before you go, lots of delicious regional dishes to try out!