. . . link about Yonezawa:
http://www.yamagatakanko.com/english/kokusai/tour06.htmlI usually visit Yonezawa during winter so the open market at the Plaza is closed. It is difficult to find a place to buy a steak meal or teishoku since as in several cities, the restaurants are spread out.
A good place to have a Yonezawa steak lunch set is near the tourist center in central Yonezawa. I guess it's called Matsugasaki Park. It's a new facility with gift shops and the tour buses stop there. There is a main intersection in front of the center. Diagonally across the street is a small restaurant with prices only in Kanji. But there is a picture of a steak lunch set at 5000 yen. Very good deal because it includes rice, miso soup, pickled vegetables, and some other side dish, all well-prepared. I've also tried Matsuzaka and Kobe beef, and this was my best experience with Wangyu beef.
When I ate Matsuzaka beef in Matsuzaka City, I paid 6500 yen for a 200 gm steak, and it didn't even include rice! Only came with a few pieces of green pepper and onion to grill.
More on beef: Yamagata Station is a couple of train stops north of Yonezawa, on the Ou Line. On the 1st floor food basement are good shredded beef obentos. Expect to spend 1000 yen for one. Yamagata is also known for it's own beef.
The Hotel Castle in Yamagata includes the city's famous beef soup (imonikai, see same link) for buffet breakfast. It's thin slices of beef simmered with taro, gobo, onions, and some other veggies. Really strong beef flavor. Again, it's one of the pluses of partaking of breakfasts at business hotels.
The Ekiben shop in Ueno Station sells Yonezawa beef obentos. These have cubed beef on a stick. Normally only one of two vendors at Yonezawa Station sells these obentos. It sells out fast at Ueno though, usually by 2 pm on weekends (it's also 1000 yen). Sometimes Seiyu stores in your local neighborhood might have them when they sell Ekiben obentos.