There is not a lot of space for buildings in Japan. People who live alone often have only one tiny room. People in Japan found ways to save space. In the living room, there may be only one table.
They might spread out futons on the floor at night, instead of using beds in their homes. In more traditional homes, paper screens, instead of walls, divide the rooms.
Frequent fires, volcanoes, and earthquakes have destroyed many homes in the countryside.
Before entering any home, they remove their shoes.
They measure the size of their homes with tatami mats.