Japan has the tradition of making a small space to concentrate on something. The tea room is a good example, and placing folding screens in the room as a divider has the same meaning, too.
“Hakoie （箱家≒box house）” has the meaning of a house like a small box. It is meant to be built in doors to make a small isolated space in the house.
The building kit is mad of wood and made by the finest craftsmen. It does not need any nails or screws to build. You can store it by dismantling it and rebuild it any time you need it.
It costs 1995000 yen for a W1840mm x L1845mm x H1870 kit and 2310000 yen for a W2314mm x L2380mm x H2170 kit. Sure, its costs a bit more than IKEA furniture, but you can have your own small Japanese room.
Translated by Elena