I lived in Nagoya for 3 years and just had a business trip back there this week. Here are my recommendations:
1 Hitsumaboshi = go to Horaiken. Supposed to be one of the best in Nagoya and I would agree. It is in the Matsuzakaya building (top floor)in Sakae. So it should be walking distance for you. Ask anyone and they will know the place.
2. Miso Katsu - There are lots of good places but one of the more popular places is a place in Osu Kanon (walking dist to sakae). I cant remember the name but look for the big pig wearing a red apron sign. They also opened a shop in a building in Sakae (overlooking central park green belt). Cant miss!
3. Ramen is my passion. Misen is a good call. But if you want to try a wide selection in one stop, go to the Nagoya train station and there is Ramen alley located near the shinkansen entrance. About 8 different styles of ramen.
4. Shabu sha bu - cant miss with Kisoji (sp). There are several of them in the Sakae area. Go for the tatami room setting.
5. There are lots of little bento box places before you jump the shinkansen to Tokyo but one of my favorite things to do is grab a variety of foods from the basement of the Matsuzakaya dept store in the Nagoya train station. You can buy a couple of musubi, a few piece of yaki tori, gyoza and make your own lunch (much fresher and with the things you like).
I could go on and on but this should get you started.