I went to a western restaurant in Japan that was “stereotypical USA” themed and there was mainly kitschy shit all over the place like advertising memorabilia (stuff m&m character statues) and of course american flag themed stuff (but iirc no actual flag)
It was a long time ago but I remember the menu was like burgers, hotdogs, mac and cheese, etc and the food was super mid. Main thing I do remember was the mac and cheese was 100% kraft dinner which was so disappointing. the burger was also weak which is inexcusable because japan has serious burger game
If your normal diet consists of healthy food like many Japanese diets do, eating authentic American food is NOT a good idea, especially southern food. I say this from experience.
I used to work down the street from another building that had a small cafeteria, but on Fridays the chef would set up a big grill outside and cook up sausages, hot dogs, burgers, chicken, and grilled veggies. It was just like going to a backyard BBQ. Those were some good Friday lunches when we made it over there.
There are a couple of "real" BBQ places, but none that I know of that would have sufficient lawn for lawn chairs. There are plenty of grill-your-own places here, most of which are Korean-style BBQ, but some of which let you grill other things. As I think about it, I don't think I've seen the type of lawn chair (like oven "fabric" style) that I was used to here; it's all just plastic molded chairs these days.
I always wonder how culturally authentic these gimmicky restaurants are. Like realistically hardly anybody in America grills food in the backyard. I do it maybe 3x/year and only in the summer. I've seen my dad multiple times grill with snow on the ground, but he was an outlier.