Hikite (te meaning hand, hiki or hikeru meaning drawing in.)
Often you see karateka using hikite,
they are sharply snapping one hand out while pulling the other hand back to the belt.
And of course there can be situations where the returning hand might be grasping the opponent to pull them in, that action used along with other actions of the defender to finish the attack, But such situations must be carefully managed to work effectively.
What I find more plausible is an entirely different use of hikite, where you use the returning hand as a slashing strike into the body, the face or even another striking arm to disrupt that attack creating a space to further utilize in the defensive mode.
That slashing fist returning to chamber is very unexpected as an offensive strike. Often seen as meaningless in itself.
Let me give one example of its use.
An opponent is attempting to grab you with their right hand.
You don’t want grabbed for you are anticipating much worse is to follow.
So you respond with intention.
You step forward, driving forward with a crescent step with your right foot,
2/3 of the step stepping toward your centerline, away from the line of their attack.
The remaining 1/3 of the time of the step to explode out from the centerline,
with the energy you gathered stepping into the centerline.
As you conclude the step your right vertical strike,
utilizing the ridge of the knuckles of that hand strikes into the arm of the grab.
At te same time your left vertical strike,
also using the ridge of the knuckles of that hand strikes into their right lower rib cage
to cause intense pain in the attacker.
The left hand then strikes up into the extended grabbing arm,
moving it out of further play at this time.
As that happens you return your right hand to chamber of your right side at your hip.
That chambering motion (also identified as hitike),
is used as a most viscous slashing backfist strike into the side of their head as it returns.
Both these arm motions are simultaneous the parry and the slashing return to chamber.
Then from the right chamber, the attacker stunned by the two strikes given,
Discovers from chamber
That your right hand has struck into the quadriceps muscle of their left leg.
That vertical ridge of knuckle strike was focused into the big bone of their left leg.
The result of that strike is an instant Charlie Horse cramp,
Causing their leg to buckle from the resulting pain and they go down.
Of course this is but one option of the use of hikite in this combination.
There is a very wide range of targets for this sort of slashing attack
It all depends on location of the attacker, the best target of opportunity
And how much you choose to do to the opponent.
There is more potential in the slightest motion than most realize.