SCA Courts à la Japonaise
If you are holding a court, whether indoors or outdoors, the jinmaku (camp curtains) make a perfect backing. For those, you should use triple-width ones (18 feet) so that the center back is flat rather than having a pole in the way. In front of the curtain a tatami dais should be rigged.
If outside, the dais may be placed on a ground cloth. The dais is not necessary, however, as the noble(s) holding court could easily sit on a camp stool, on item of modern SCA camping gear nearly identical with that of the Japanese.
On the dais would be a stool if necessary, or preferably a seat cushion (zabuton) and perhaps an arm rest (kyōsoku) and a sword stand (katana kake). (Alternately, a sword bearer would kneel behind the person holding court.) If two people are holding court — something unheard of in old Japan, but common in our Society — put up another stool or cushion; either way only the man would use an arm rest. If it is cold, a hibachi or other brazier may be placed in front of the dais for warmth. If not cold, an incense burner may be there if desired. Behind on the dais may be placed a suit of armour (yoroi) on its stand.
This same arrangement could be used in a hall for a Japanese court.
Note that this is for a military (buke) court. If the holder chooses to do a civil court, there should be no sword bearer or sword stand, and the garb would be different.
Civil and military courts have nothing to do with wearing armor. A civil court is held by a court noble, so the noble wears civilian garb. "Military" courts are held by members of the military aristocracy in or out of armor. With the doubling of titles, an SCA king or baron could hold either court as it suited his fancy.
Japanese courts have always been hierarchical things. The noble holding court would be the focus, along with any immediate retainer(s) (e.g.: heralds or sword bearer(s)). Next down would be the inner circle of retainers, the highest ranking guests, and perhaps close friends. If the presiding noble is in the territorial fief of a subordinate (say, a king in a barony or principality), the noble holding the land in fief would be at this second level. On the third level would be the others.
For those who saw the film Kagemusha, there was a scene in which the double, impersonating Shingen, was presiding over a council discussing what to do about Ieyasu's attacks. The generals sat on small cushions lining one wall, facing across the lord's line of vision, only turning - and turning their whole bodies, bowing first to face the lord when they spoke, bowing and returning to their former attitude after speaking. The lord was along another wall. The wall opposite the generals was open, and the rest of the clan sat outside there.
This is quite accurate.
Deportment in Court
The holder of the court generally would not themselves stand for any reason, whether to congratulate someone or receive a presentation.
Someone else, perhaps a herald or specially assigned retainer, would receive scrolls, gifts, or other objects, and bring it to the one presiding. They would likewise hand out any scrolls or tokens that might be required. If the presiding noble wished, they might step down to offer congratulations or to accept presentations, but note that in Period Japan this would be a pretty phenomenal thing for someone to do.
When presenting something in court (a scroll, for example), it should be held out in front of one with both hands, arms extended forward. The body should be slightly bowed, so that the head is between the arms. The recipient, if an equal or lesser, or a retainer passing it to a lord, receives it, arms extended, and brings it to their forehead giving a nodding-bow. (People of superior rank, of course, may do whatever they wish.)