Most likely not. To be honest the potential poisoning of all the children and us being criminally liable for that was kind of a deal breaker for us, so we did not really get into the nutrients.

Definitely not; we don’t eat it that often even in Japan. While yes we have fast food variants of sushi that are readily available; it’s overall more of a special dinner/occasion type food. I probably eat sushi once every couple months.

The only thing I could see being included in a lunch is something like inari-zushi, my office serves that as a side dish lunch a lot (which would get around the food safety concerns). We have chiraishi zushi at the office specifically on Girl’s Day, because it is a holiday thing.

An elementary school might have something similar on holidays, but generally the school menus are planned by a nutritionist on staff that does a pretty good job. It gets tricky for kids with special diets, which are often not well accomodated, and there is a weird obsession with milk despite the prevalance of lactose intoelrance.

EDIT: We have a massive food waste problem too, so we are no better in that regard, but at least our school lunches are pretty good.