kami-sankaku-gatame
(upper triangular hold down)

"This hold starts from a possition similar to 'kami-shiho-gatame.
Tori holds Uke's head and right arm, forming a triangle with his legs. Tori's bent left leg encircles Uke's neck and arm. Tori's left instep overlaps in the popliteal hollow of his right knee. Tori wraps his right arm under Uke's waist and takes hold of Uke's belt."