Social norms derive from commom axioms (core ideas) the group of people have. Things like Japanese people think the ground is dirty, so they remove their shoes when entering many buildings. Not just homes, but some hospitals, dentists, offices and museums will expect you to remove your shoes. Also many Japanese fear leaving a fan or heater on as you sleep can burn down the house, so they turn them off or use a sleep timer - meaning you wakeup to a cold or hot room. Japanese also after years at school cleaning up after themselves are more inclinded to think making a mess in a public space like cafe is embarrassing. I'm not sure the reason. But Japanese don't think it's acceptable to volunteer to do something, they often play scizor/paper/rock to pick people. Also when asked a question in class ir a meeting will ask their friends for help (usually saying their answer to the people clise to them before saying it loudly for everyone to hear). I think you will be better to look for some of these axioms that dictate what is acceptable and unacceptable. You may even find common traits with your home, but have a different reason. Axioms can help you understand parts of the grammar and expressions in the language too.