Can be a specialty roll or something common!
Specialty rolls aren’t really a Japanese thing; fancy maki sushi (rolls) with lots of fillings and topping are pretty rare in Japan! They’re really more like American-Japanese or wherever-Japanese food. 😉
But if you love some really high quality nigiri sushi (simple sliced fish, etc on top of a nugget of rice) then you’ll find some good stuff in Japan. I think the best route is often to find a shop with a good reputation and then try their omakase, so whatever the sushi chef recommends that day! It can also be fun to try like a maguro (tuna) tasting plate, with various cuts (everything from lean “red meat” to really fatty otoro).
Yeah, seasonal omakase tends to be a great choice! I didn't know what to expect when I visited Sushi no Midori recently, because it's a chain, but this set was ridiculously good.
Seasonal ingredients or local specialty would be my option. Especially if you have the chance to go around the country.
I can't wait to eat tons of salmon sushi in Japan! Lockdown is basically forcing me to save a lot of the money I'd normally spend every day, but I think I'm going to end up spending it all anyway once we can safely go out again.