Chests and Boxes
There were many kinds of chests and boxes used in Japan, ranging from small ones designed to hold writing equipment to large ones designed to hold suits of armor or household goods. For tournament or event use, there are two types that immediately come to mind as convenient for stashing large amounts of gear.
(In the interest of space, rather than provide diagrams on their construction, I will just give a clear look at the chests. Anyone with a modicum of skill in woodworking can easily make them, anyway.)
One of the most common chests from Heian days was what was called a karabitsu or “Chinese chest”. It was generally about the size of a footlocker, and it became the standard receptacle for the armor of the nobility, as well as being used in the home as a catch-all for other boxes or slightly bulky items. Its most distinguished feature is the six legs. More ornate versions were made, with complicatedly-cut feet, but for day to day use such niceties weren't of major importance.
A legless variety also existed, but it was not called karabitsu. It was merely a big box and would seem to have been called a hitsu, the generic term for "chest".
Another chest, about the size and shape of a footlocker on end, was used for armor from the mid-1500s. It had handles and was designed so that when the handles were up, the chest could either be carried by them, or have a strong pole thrust through them and thus carried between two people or over the shoulder of one strong man. Some were fitted with shoulder straps to enable one to carry them on the back.
The usual decoration was black lacquer, though other colors could be used. Some chests were very ornately decorated, with overall repetitions of the owner's mon, or simply a repeating pattern or design.
One item of gear useful for courts was the armrest, or the kyōsoku. Its construction, too, I will leave out, although the enclosed illustration should provide enough of a hint as to how best to build one. Considering that chairs weren't used in Japan, the armrest's usefulness can be readily apparent. They measured usually some 18 x 6 inches. Height varied but hovered between 8 and 10 inches.
The Japanese camp stool, called agura, is identical in all respects to the standard flat, canvas topped camp stool seen in the West and still in use today. These stools were never used indoors. Their most common use was in the camp, as sitting down on the ground in Japanese armor and standing again quickly is not simple. They can be used at simple outdoor events as well when you don't want to sit on wet or dirty ground.
Zabuton, or seat cushions, were and still are a common piece of indoor furniture. Their best usage for the SCA could be for indoor courts; they would give the court-holding nobles a place to sit.
There were principally three types of seat custions. The most comfortable is a simple square cushion about one and a half feet square and about three to four inches thick. It can be decorated with a mon or other motif, or even left solid color. This is the zabuton proper.
Another "cushion" - though really more at something to keep the backside clean - is the enza or "round seat". The enza is a spiral of rope sewn together. (I have known people to make replicas of these by making a rope spiral and liberally applying glue to the bottom and permanently setting it on a small wooden disk.) The enza is about 18 inches in diameter, although they could be as small as a foot. They're not really very comfortable, but they keep the behind out of the dirt.
A third seat, which all but disappeared after 1400, is the shitone, which looks like a mini tatami. It was used mostly by the court aristocracy, but it did catch on with the military aristocracy later. See the section on tatami for information on its construction.