Ma-ai  - Distance

In Kendo Ma-ai means the distance between your body and the opponent. For illustration purposes the diagrams below show the separation by use of the shinai.

There are three main physical distances:

To-ma-ai 

The long distance. The kensen(tip) are at a long distance away from one another . The distance to cover lo strike your opponent requires more than one step. It is a position of safety but also one from which it is difficult to strike. Tsugi-ashi footwork is commonly used from this distance to spirng suprise attacks.

Issoku-itto-no-ma-ai 

This is the distance of "one step one cut".  At this distance the kensen are between barely touching and  as deep as nakayui crossing . An attacker should be able to make their cut in one step forward. Just the same the attacked could avoid a cut with one step backwards. This is the most important distance in kendo as you are both protected by having the evading distance available to you and you are in a strong position to attack.

 Chikai-ma-ai 

The close distance. Shinai cross in the nakayui area or deeper.  If you are a beginner you will find that this is the most familiar distance as you lack confidence in your reach for a cut. You must beware of this distance however, as it is easy for the beginner to get entangled, or just whack out rather than cut correctly. Whereas the more advanced Kendoka will use this distance with more ease by increasing distance for the cut.