article 6 Judging tanto tsuki (from the rules book 2008)
Tanto tsuki ari apply the concepts of the stab and straight cut from kendo and the principle of kikentai no itchi (unity of mind, sword and body). They are an extension of tegatana dosa (sword hand movements taken from Tomiki's judo taiso around 1950)
Valid areas : front sides and back of the chest, arms when they arein contact with the chest.
Upright torso and stable hips at the instant the tsuki finishes. Tsuki are perpendicular to toshu's bodu (unarmed person)
Tsuki start by stepping forward from issoku itto distance (one step distance).
This is a sports form of aikido randori, it teaches us good reflexes and correct judgment of distance. The purpose of randori is to find out if our techniques and movements are in the area of "skill". If you enter shiai or randori training you will find out very soon if you have the skill to defend yourself against a very simple attack and also against someone who is not cooperative.
For Tomiki, budo is the training of kokoro (here refering as mental), this kokoro has to remain immovable even in a decisive situation. In modern society the competiton area is the only place where we can practise our "kokoro" or immovable mind without the chance to become severe injured or slaughtered to death
After all aikido is the way of harmony and not the way of injury or death.
Only after entering the field of shiai, you can understand what is happening and how difficult it is to have an immovable mind. The fear of losing is always around the corner and makes the body frozen which results in "non"flexible techniques and hitting the opponent with the purpose to damage him.
This you cannot learn with "kata" practice alone.