Many people first meet shikibuton in Japan at a ryokan, an onsen hotel or a small guesthouse. The sleep can feel simple and calm: tatami under the bedding, a quiet room, the futon laid out only for the night. What guests usually do not see is the morning work. The futon is lifted. Sometimes it is folded. Sometimes it is turned or aired. That habit is not decoration. It is part of how this bedding is meant to be used.
A shikibuton is different from a thick mattress kept on an open bed frame. A bed frame has space underneath, so body warmth and moisture can move through the mattress and into the air below. A shikibuton is often closer to the floor. If it is laid on wood, tile, tatami, a platform board or another flat surface, the underside has much less room to breathe.
Why moisture gathers underneath
During sleep, warmth and moisture move down through the bedding. When that warmth meets a cooler floor or platform, moisture can remain on the underside. If the futon stays pressed flat in the same place, the bottom side cannot dry well. Over time, that dampness is what causes trouble. The point is not that shikibuton is fragile. The point is that cotton and fibre bedding should not be kept damp and sealed against a surface.
This is why Japanese futon care begins with movement. Lift it. Fold it. Let the underside meet air. Turn it sometimes. Change the head-to-foot direction now and then. These small actions spread out pressure, let the filling recover, and help the bottom side dry before moisture has time to settle in.
The habit changes by climate
In a humid place, the futon may need to be lifted more often. In Singapore, Hong Kong, Taiwan and other warm, damp homes, the room can feel comfortable with air-conditioning while the underside of floor-used bedding still has little airflow. In the UK, Ireland or parts of Europe, winter can be the season to watch: rooms stay closed for warmth and floors or walls may be cooler. In Canada, Finland and other cold climates, even dry indoor air does not remove the need for floor-side airing because the temperature difference can still matter.
Large countries are not one climate. A coastal Australian room is not the same as a dry inland room. A home in the Pacific Northwest is not the same as a room in the American Southwest. The care is not complicated, but it should respond to the place: where air is damp, lift and dry more often; where the air is dry, still turn and air so the filling does not stay compressed in one position.
How to care for HIMARI and SORA in daily use
- After sleeping: raise or fold the shikibuton so the underside can breathe before it is put away or laid flat again.
- Through the week: turn it over sometimes, and change the head-to-foot direction so the same part is not always under the heaviest pressure.
- When the weather helps: air it in dry conditions. In Japan, airing is a normal part of futon life, not a repair step.
- Before storage: make sure the futon is dry. Do not store it while damp.
- When the room is humid or cold at the floor: pay more attention to the bottom side, because that is where moisture is easiest to miss.
What changes after years of everyday sleep
With daily use, regular airing, dry storage and normal care, a traditional shikibuton will settle over time. As a practical reference from everyday Japanese use, a futon used every night may enter a replacement cycle after about 3 to 4 years. HIMARI begins at about 10 cm and SORA at about 12 cm; after years of sleeping, folding and airing, the thickness may naturally settle by several centimetres.
That change is not a sudden failure. Soft bedding materials become more compact where they receive weight night after night. Some Japanese households keep an older futon for guests, for backup use, or as a lower layer after replacing the main sleeping futon. The main lesson is simple: if you want the comfort people remember from Japan, keep the Japanese habit with it. Air it, turn it, keep it dry, and do not let one side stay sealed against the floor day after day.