The Tomoe-nage (Circular throw) Waza consists of submarining under the opponent and throwing him with a leg throw.
From the natural posture, Tori waits until Uke makes a lateral move. At that moment, Tori bends his knee and kicks off, launching a forward roll with his body curled into a tight ball, and submarines beneath Uke.
Tori then places a foot against the upper part of Uke thigh (where it joins the torso), and then uses the spring force of his bent knee to throw Uke by kicking upward.
Tori uses his Tsurite (Lifting hand) and Hiki-te (Pulling hand) in tandem with his kicking force.
The Tomoe-nage (Circular throw) is a Ma sutemi waza (Supine sacrifice techniques), and is used in both men's and women's competitions.
The kicking throw can be executed directly backward, or it can be executed laterally in conjunction with lateral motion. The lateral type throw is more common in competition.
The lateral type throw favors smaller combatants because the submarining maneuver is relatively easier for them to perform. It is therefore executed more often in the lightweight divisions.