From closed guard, an arm drag can be used to set up a back take.
Tori grips uke’s hand using a straight grip (tori’s left hand grabs uke’s right), pushing it into uke’s belly.
Tori uses their other hand to underhook uke’s arm between their inner arm and side of their body/ribs.
Tori initiates the arm drag, simultaneously pulling themselves towards uke’s back and hipping away from uke, making it easier to control uke’s back.
As tori arm drags, they let go with the wrist grip and reach across uke’s back, grabbing a hold of the lat muscle or armpit of uke to help pull into the back take.
If tori has long arms, they can “grip” the armpit/lat with their forearm, while also curling their wrist so that their thumb/lower forearm can be used to hook the armpit/lat of uke.