Photo 1, tori's right foot is positioned for ikkyo omote. Photo 2, tori's right foot is positioned for gokyo omote, 180° from the previous position.
Studying of the kajos leads us (among other things) to the following discovery: the 180º angle between the two pictures represents the half sphere of the five omote immobilization techniques. The adjustment from ikkyo to gokyo is done with the front foot movement with a 180º arch. On this half circle, the successive angles determine the directions of the techniques:
IMPORTANT: the movement done by the right foot between ikkyo omote and gokyo omote is called tai no henka. We will understand this point a bit further down.
In order to make it more visible, let's put that omote half sphere in our reference figure:
Photo 1: tori's right foot is positioned for ikkyo ura. Photo 2: tori's right foot is positioned for ikkyo ura.
We now know that ura is the other side of omote and that all omote immobilization techniques have an absolutely symmetrical twin in the following ura half sphere:
IMPORTANT: the movement done by the right foot between ikkyo omote and gokyo omote is also called tai no henka.
It is not the tai no henka we generally think about, the one we practice at the beginning of every training, passing in uke's back, the key of all ura immobilizations. But the movement we saw above in the omote half sphere is the same in all aspects. The only difference is that it allows to apply all the techniques in the half sphere in front of of uke's stomach. And what makes us stay in omote half sphere or enter into ura half sphere is nothing else but the initial step forward done with the back foot just before launching the rotation in in uke's back.
It won't escape the reader that the same picture illustrates in this kajo #18 both gokyo omote and ikkyo ura. What is the meaning behind?
In order to understand the link between the two half spheres omote and ura in terms of footwork and movements, we need to remember the amazing discovery of kajo 13 and start from there: gokyo and ikkyo are the same technique seen from two different sides form two 180º opposite sides
If, 180° opposite to ikkyo omote, we find gokyo omote and if at the same time, at 180° opposite to ikkyo omote, we can find ikkyo ura with the same rotation (ue kara shita made), then it can only mean that gokyo omote and ikkyo ura are the same thing. In other words, there is in fact neither ikkyo or gokyo, there is ippo, the first law. Gokyo omote and ura are, on account of the very necessity of footwork and movements, twin movements. The only element of differentiation, fundamental though, is the nature of the tai no henka, which, launched in uke's back, puts ikkyo ura at the very beginning of the ura half sphere while, kept "in front" of uke, it puts gokyo omote at the very end of the omote half sphere. These two movements are separated by the thickness of a cigarette paper.
After that precision, we can understand now how modern Aikido thought gokyo omote as an ura form. The proximity with ikkyo ura was the source of that misunderstanding.
Let's put the ura half sphere in our reference figure as we did for the omote half sphere: The two half spheres put together give the following figure where the angles are calculated with the roppo key as origin and not the polar axis of uke's attack: Philippe Voarino, June 2012.
Aikido is not a sport, it is a martial art which laws (takemusu) are in harmony with the laws of the universe. Studying them allows the practitioner to understand his place in the universe. Aikido was born in Iwama, O sensei achieved in that village the synthesis of tai jutsu, aiki ken and aiki jo.
The International Takemusu Aikido Federation (ITAF) brings to the practitioner the structure he needs in order to work as close as possible to the reality O sensei MU defined. The official national representations are the guarantee of a teaching faithful to the Founder's.
In modern Aikido, weapons are hardly taught, if taught at all. In O sensei's Aikido, on the contrary, aiki ken, aiki jo and tai jutsu are unified and form together a riai, a family of harmonious techniques stemming from one unique principle. Each techniques helps understand all the others.
Peace is a balance between a human being and the world around him. The true martial art's goal is not to become stronger than one's opponent but to find in that opponent a way to realize harmony. There is no enemy anymore as such, but an opportunity offered to reach unified ki.