Wait, so Kaoru might be from a wealthy family?
Haruka is from a wealthy family, so no wonder she most likely didn't had instant food, although spent some time in school but probably ate at home mostly or restaurants...
It's funny how "additive" is a scare word, either go and try to make things old way and the price will be extremely high or face the reality, we know about how things are made while skipping the process.