Iriminage (entering body throw) is the quintessential Taikyoku Budo technique because every technique in Taikyoku Budo begins with irimi. Irimi is the principle of taking space, displacing one’s opponent’s body with one’s own.
As Ellis Amdur explains, “As the enemy cuts, so, too, do I cut. Not ‘along’ the same path. ON THE SAME PATH. Two objects cannot occupy the same space, and I, with greater power/speed/timing/postural stability, etc, take that space. The enemy is, ostensibly, deflected, but they are NOT knocked away… This, by the way, is the true essence of atemi—not pugilism—but using the body (particularly the limbs) to take space the opponent is trying to occupy. ”
Iriminage is a stylized throw that is the physical manifestation of this principle, but, with proper physical and mental organization, all body throws essentially become iriminage, ie a throw resultant from irimi.
In this image, we see Reyadh applying osoto gari (large outer leg reap) on Paolo. One way to think about osoto gari is that it is iriminage with a leg sweep. This is especially useful when uke (the person receiving the throw) tries to counter tori (the person applying the throw) with irimi of his own, in this case by turning into tori and applying an underhook. The leg sweep is a great way to counter this counter, such that partners exchange irimi until one is finally thrown.
-Robert Van Valkenburgh teaches Taikyoku Budo and Brazilian Jiu-Jitsu at Kogen Dojo
Meditations on God 