* Summary:
This Ashi waza (Foot / leg techniques) displays instantaneous leg / foot work.

* Features of this Waza:
The Kosoto-gake (Small outer hook) consists of advancing toward the opponent, and then placing a foot behind the opponent to throw him down onto his back.

* Waza details:
Although this Waza closely resembles the Kosoto-gari (Small outer reap), its advance against the opponent is deeper when performing the throw.

Tori (Player executing technique) feigns an advance against Uke (Player receiving opponent's attack), and then withdraws, pulling him forward, waiting for the moment when Uke (Player receiving opponent's attack) steps forward.

When Uke (Player receiving opponent's attack) pushes back against the advance, Tori (Player executing technique) feigns a retreat, but actually advances to hook the heel of Uke (Player receiving opponent's attack) advancing foot.

Tori (Player executing technique) then pulls Uke (Player receiving opponent's attack) in the direction of the hooked foot while also grasping Uke (Player receiving opponent's attack) uniform between his shoulder and chest with his Tsurite (Lifting hand), lifting Uke (Player receiving opponent's attack) to destabilize and throw him.

In combination with both his arms, Tori (Player executing technique) also places the bottom of his forward-leg foot against Uke (Player receiving opponent's attack) weight-supporting leg, and then uses the spring force from the knee of his own supporting leg to throw Uke (Player receiving opponent's attack) backwards in a diagonal manner.

* Waza usage tip:
This Waza is used as feint in the moment that Uke (Player receiving opponent's attack) shifts his Center of gravity to his forward leg.
While guarding against a counterattack (such as an Ouchi-gari (Large inner reap)) when all his weight is on his supporting leg after hooking Uke (Player receiving opponent's attack) foot, Tori (Player executing technique) then executes the throw with a swift leg action.