Only one person can swing a sword at a time, everyone else has to wait outside.

The real reason they stopped fighting when their scabbards touched each other, every time you turn or take a step.

Doing syncronized line kata you put your sword away, look down and find you had resheathed into your classmate's scabbard.

The whistling of the swords are deafening in the tiny space.
Jikishin kore dojo nari