The design a Japanese futon is, well, Japanese!
What makes a design Japanese? The item is useful, easy to clean, and
maximizes the use of space.
http://www.paleobunker.com/wp-content/uploads/2013/03/traditional-japanese-futon.jpg |
The coverings are washable. The futon itself is taken out on sunny days and hung on a railing to air out. Thy are also beat with a wand to get the dust out. This is the same way western floor rugs were cleaned before vacuums.
A futon maximizes the use of space because when it is not in use, it is rolled/folded up and moved close to a wall, thus freeing the space to serve for more than a bedroom.