Japanese houses compared to American ones
Japanese houses don't have cellars or basements. It is apparently prohibited by laws. What a waste of space in crowded cities like Tokyo. No wine cellar, no additional place to store food, but since they don't normally have central heating, so they don't need central heat. Japanese houses have no attic or loft. That may also look like a waste of space, but actually, they are often built on 3 floors instead of 2, so the attic is just an additional floor right under the roof (which means freezing in winter and stifling in summer).
Many new Japanese houses have flat roofs with a terrace on the top. This is a creative gain of space - convenient to dry the laundry. As it rains much less in Tokyo than anywhere in Northern Europe, that's fine. Walls are thin (about 10cm) and hollow. It's almost possible to destroy them with a kick or a small hammer. That is because of earthquakes and gives a feeling of "paper house" to the habitations. This is in sharp contrast to the American stone or brick walls thickened by an additional layer of thermo insulation (glass fiber...) and plaster, which Japanese houses almost never have.
As I mentioned above, central heating is uncommon and so is floor heating (this is because they have wooden floors everywhere instead of tiled floors, so cold on the feet in winter). Japanese heat themselves mostly with portable "gas heaters", not fixed electric or fuel radiators. American houses have air conditioning, because summers are hot enough in the South are very dry in the southwest, so that the shade and thick walls are enough to keep it cool inside. All Japanese houses (except in Hokkaido) have air conditioning in almost every room, as it would be unbearable during the muggy summer without it. Windows and doors normally open by sliding, especially in slightly older (can be very old in Japan) or traditional buildings. Window frames don't have partition in the middle.
Rooms and utilities
On top of the lack of cellar and loft, Japanese houses very rarely or never have pantry, study room (probably only big houses anyway), utility room, garage. Japanese rarely have a dishwasher or tumble dryer (even though they make the 2 in 1 models with washing machines now, if space is an issue). The bathroom is usually small because it is limited to the bath and shower space, without "dry ground", nor furniture (for the towels, soap, cosmetics...) or sink to brush your teeth, make up or shave. Everything is outside the bathroom, sometimes on another floor (e.g. on the landing between 2 rooms or next to the entrance hall).
Japanese houses in big cities very rarely have a garden. The architecture is very standardized, all in concrete, and only the color of the fakes bricks or painting differentiate them. This is true from the Northern tip of Hokkaido all the way through the 3000km down the Southern reaches of Kyushu. Needless to say that American architecture vary not only by geographical region but equally inside a same city of village, due to the quick evolution of styles in time.
Eating Out In Japan...
Entering and sitting down
Many restaurants in Japan display plastic or wax replicas of their dishes at the entrance. They usually look very similar to the real dishes. When you enter a restaurant, you will be greeted with the expression "irasshaimase" ("please come in"), as it is usual in any Japanese store. Waiters and waitresses are generally trained to be extremely efficient, polite and attentive, and will usually immediately lead you to your table. If they don't, you can assume that it is okay to sit at any table. While a majority of restaurants in Japan are equipped exclusively with Western style tables and chairs, restaurants with low traditional tables and the customers sitting on cushions on the floor, are also common. Some restaurants feature both styles side by side. In case of a traditional Japanese interior, you are usually required to take off your shoes before stepping onto the seating area or even at the restaurant's entrance.
After you sit down, a glass of water or tea will be served for free and later refilled. You also receive a wet towel (oshibori) for cleaning your hands. If chopsticks are not already set, you can usually find some in a box on the table. Most often, they are wooden chopsticks that need to be separated into two before usage. In case of some restaurant types, for example izakaya or Chinese restaurants, it is common for all people at one table to order and share various dishes. At restaurants that serve set menus, bowl dishes (e.g. domburi or noodle soups) or Western style dishes, on the other hand, each person usually orders and eats one separate dish.
The bill will be given to you upside-down when you receive the meal or after you finish eating. In most restaurants, you are supposed to bring your bill to the cashier near the exit when leaving in order to pay. Some restaurants, especially cheaper ones, have different systems for ordering and paying. At some stores, you may be required to pay right after ordering, while in others, you are supposed to buy meal tickets at a vending machine near the store's entrance and to hand them over to the staff in order to receive a meal. In restaurants in Japan, it is not common to pay a tip. When leaving, it is polite to say: "gochisosama deshita" ("thank you for the me