When is a sword...

Following on from the current debate, I read somewhere of a samurai
sleeping with a 'night sword' close at hand.

I have always assumed this to be a wakazashi/kodachi/whatever,
generally a short-bladed weapon more suitable indoors - avoids the
embarrasment of getting your blade stuck in the rafters as you assume
an intruder-terrifying jodan kamae!

As an aside, in Gohatto there's a scene where an older samurai
instructs the protagonist to 'choke his sword' when fighting indoors -
a grip with both hands almost touching that would significantly reduce
the blade's 'arc of operation' as it were.

Thomas