As everyone knows, living in another country requires not only a whole new vocabulary, but a whole new set of cultural rules. Before I came to Japan (and even when I got here), I heard a lot of things about Japan's cultural rules. Some advice was good, and some turned out to be just plain wrong.
One place in the home that doesn't really have an exact equivalent back home is the genkan. Basically, the genkan is an entrance room. The genkan is where you leave your shoes before you step up into the house. It's pretty handy, because it usually has a concrete floor. My apartment has some nice shoe storage as well as places to hang coats and various other winter items. My toilet is also out there in its own tiny room.
Before I came to Japan, I heard that the genkan area was considered by some to be a public space and salespeople might just walk in to that area if the door was unlocked. It took almost a year, but today I discovered that advice was correct when a stranger opened my door and started talking! Thankfully, I remembered the Japanese phrase for just a minute, and he went away.
Even though I had heard that advice last year, I was still really surprised when it happened! Normally, I leave my door locked, but apparently I just forgot when I came home this evening>