Only those who understand the depth of its meaning reach a high level of proficiency. Karate-Do is a martial art and as such has no end or explanation in itself. It is through a process of hard training and rigorous discipline that we try to understand and reach the Way (Do).
The "Rei" may be defined as the will to establish a relationship based on mutual trust, goodwill, understanding, and respect of individual feelings by showing respect.
The "Reigi" (manners) is the way of expressing this concept. Those who learn Karate-Do must understand the depth of the meaning of "Rei" and always behave according to the principles of "Reigi".
In another meaning, "Rei" is a ceremony or a formality that two people facing each other exchange mutual signs of their respect and trust.
"Saho" means "proper etiquette" and is the way of how to execute correctly the "Rei" in training or in Kumite.
In Kumite, two partners face each other, in the position "Shizentai Hachiji Dachi", then they move to "Musubi Dachi" (heels together), the attacker (Semete) bringing his right foot to his left foot and the defender (Ukete) his left foot to his right. They look at each other in the eyes for a moment. Then, leaning forward with the upper body straight, at an angle of approximately 30 degrees with a total view of the opponent’s lower body without staring at any specific point (one second). They straighten up, look at each other in the eyes and then resume the stance "Shizentai Hachiji Dachi".
For instance, in "Gohon Kumite", "Sanbon Kumite" and "Kihon Ippon Kumite", at a certain distance (Maai) from "Shizentai Hachiji Dachi", the attacker (Semete) steps back with his right foot (or left) to "Zenkutsu Dachi" , "Hidari" or "Migi" "Gedan Barai" and informs his opponent of the target and type of attack, while the defender (Ukete) maintains his position. The attacker (Semete) by taking a step back to get into position is displaying a "Reigi" (manners) to his opponent. Conversely, when training in basic techniques (which do not involve an opponent), practitioners step forward to get into position to display their fighting spirit.
After the defender has completed his counter attack both attacker and defender one again return to thier initial positions of "Shizentai Hachiji Dachi" by inhaling while bringing the displaced foot back, then exhaling while tensing the abdomen (HARA) with the feeling that the "Ki" is in the lower abdomen ready for the next movement.
It is of utmost importance that breathing is linked to the proper movement and awareness of the situation, whether executing "Rei", taking a position, or practicing "Kumite". Always remember that breathing has a very great influence not only on the health, but also on the physique, ability, technical level (power and speed) and the brain.