Japanese Sword Etiquette
To touch another’s weapon, or to come into collision with the sheath, was a dire offense, and to enter a friend’s house without leaving the sword outside was a breach of friendship. Those whose position justified the accompaniment of an attendant invariably left the sword in his charge at the entrance or, if alone, it was usually laid down at the entrance. If removed inside, it was invariably done by the host’s servants, and then not touched with the bare hand, but with a silk napkin kept for the purpose, and the sword was placed upon a sword-rack in the place of honor near the guest and treated with all the politeness due to an honored visitor who would resent a discourtesy. The long sword, if two were worn, was withdrawn, sheathed, from the girdle with the right hand—an indication of friendship, as it could not be drawn and used thus—never by the left hand, or placed on the left side, except when in immediate danger of attack. To exhibit a naked weapon was a gross insult, unless a gentleman wished to show his friends his collection. To express a wish to see a sword was not usual, unless a blade of great value was in question, when a request to be shown it would be a compliment the happy possessor appreciated….
— The Overlook Martial Arts Reader, pp. 44-45