What to see and do in Nagoya?

As a tourist who will be in Nagoya for one Sunday ( 10 am - 4 pm), what are the must see places and Japanese food I must definitely try? I need to return back to Tokyo after 4 pm

Personal opinion is to skip Nagoya and go to Tokyo at 10am. Arrive at noon. Either go to Akihabara or Harajuku since it is a Sunday afternoon.

Science museum is very good (and large planetarium).
Nagoya Castle is one of the largest in Japan - nice grounds and recently renovated/rebuild palace.
Maglev/railway park is one of the top five attractions in Japan.
Toyota Keikan (out of the city/reservations required), or Toyoda Commerative museum.

If you had more time, there is other stuff to see/do, but those are a couple of suggestions for the city.

If you have a day, I also recommend Nagoya Castle. The rebuilt palace/residential quarters are fascinating. There is also a shrine worth visiting, but I have not made it there yet so I cannot comment on that.

For food, it depends on what you like, but "miso katsu " is a must. You will find some restaurants around/in the station.

Unagi is famous in Nagoya and Miso Katsu as a poster above said. I enjoyed the castle, and I also really liked the Toyota Techno Museum. I am not really a museum person, and I don't care about cars/electronics one way or the other, and yet I found myself pretty fascinated by it! It takes you through the history from when Toyota was a textile company through switching to cars, and has lots of interactive stuff. My husband liked it so much he actually went back a second time because we didn't have enough time to see all the shows the first time around!

And I hate it when people tell you "just skip it" on these forums. Its all a matter of opinion; people who don't care for temples could easily say "just skip Kyoto" but what a shame for most of us, right? And for me, Akihabara is totally skippable, yet probably most people would disagree with me. So... yeah. Nagoya is really nice and definitely worth even a short visit. Its also good to break up the trip if you'll be in Tokyo a long time and planning on seeing the Tokyo sights anyway!

If one is finding themselves hating others personal opinions? Then the forums aren't for them.

Forums are a communication medium that allows opinions, ideas and information to be shared. Like these forums, all those things flow together. Anyone reading should use the forums to pick and choose the information that they want.

Enjoy and learn. Don't hate.

It can be annoying to be told to skip a place, because the asker has committed to the location. Saying "skip it" dismisses the entire question. For someone who asks "What to see and do in Nagoya?" it can be annoying and frustrating to get the response "Skip it". It doesn't answer the question.

I like Nagoya. I'd say Japan-guide lists most of the top sites; the Railway Museum is top-notch and the aquarium is quite nice, too. Nagoya Castle recently opened one of the rebuilt palace buildings, so there is an extra reason to go. The Tokugawa Museum is a really nice museum. Atsuta Shrine is worthwhile for its history and importance and Shirotori Garden nearby is a nice strolling garden. Nagoya TV Tower is small, but if you like towers, it was the first in Japan. It's also in Sakae, which is a popular area for shopping (and nightlife, but you won't be around for that).

If you just want to stroll about and sample foods, Osu is a nice area. There are also maid cafes there.

Nagoya is famous for miso-katsudon, miso udon, and chicken wings. It's also famous for its "morning"s which are toasted bean paste sandwiches. There are places to get this any time of day if you want.

There is more than enough to do in Nagoya to fill your time.

If the OP had asked "should I go to Nagoya or just continue to Tokyo?" then saying "no, skip it because..." is constructive. But the OP is asking for advice on things to do, so saying "skip it" is completely ignoring the question.

Firas II I believe?

The "because" was personal opinion. As per the start of my response.

My personal opinion of Nagoya is negative and since the person may choose to ignore my info and still go to Nagoya. I kept the negative to myself.

"Must-see/do": hmm, tough question, mate - depends mainly on your personal interests. Start here:

http://www.japan-guide.com/e/e2155.html

Personally, I think Nagoya's a fine place to spend a couple of days in: great museums, rich history, awesome food, and a whole lot quieter than the tourist madhouse that Kyōto's turned into in recent years (note that I love Kyōto, I just don't think the infrastructure has kept up with the surge in visitor numbers). My own recommendations will be quite similar to those already mentioned: Nagoya Castle (along with its splendid palace), the Tokugawa Art Museum, and the SCMAGLEV and Railway Park are my personal favourites. More here:

https://withinstrikingdistance.wordpress.com/tag/nagoya/

With your limited time in the city, I'd probably just keep myself to the castle and the Tokugawa Art Museum (both are within the city centre and easily accessible via the tourist loop bus), plus time in between to enjoy a leisurely meal. Throw in the Toyota Commemorative Museum of Industry and Technology if you've got time before catching the shinkansen back to Tōkyō - it's just a short bus ride (or a rather long walk) from the main railway station.

The SCMAGLEV and Railway Park is a great place to visit if you're into trains, but it's a little out of the way (easily reached by train but the one-way ride out of central Nagoya takes about half an hour).

As for that leisurely meal, more on what to eat in Nagoya here:

http://www.japan-guide.com/e/e3315.html

Cheers.

If I had time for just one meal in Nagoya, I'd probably go for unagi (charcoal-grilled eel), at one of the branches of Bincho or Horaiken listed here: http://bento.com/ra-nagoya.html

Miso nikomi (udon noodles in a heavy miso broth) is another good option, with flavor very unique to Nagoya. And of course miso katsu, as mentioned above.

go to an onsen in the near surroundings...

I also recommend you to try unagi, miso nikomi or miso katsu as already mentioned above.

Bincho and Horaiken are both popular branches among Nagoya locals.

If you choose miso katsu or miso nikomi, Yabaton(http://www.english.yabaton.com) or Yamamotoya(https://goo.gl/maps/EKCGAr4WNVr) are popular.

Nagoya is famous for unagi and tebasaki (chicken wings).

If you happen to be there on the 18th or 28th of the month, there is a flea market in the grounds of Osu Kannon temple. Saw a lot of interesting things there.