While there might be more to it, Rika accepts the explanation for now.  But that doesn't mean Izuna is off the hook.  As promised, her petfuck will get her just desserts.  She goes over to one of the drawers of her cabinet, giving Yuka's petfuck a moment of reprise from her torment, and brings out another coil of rope.  Rika returns to her hanging victim and call on her pouting petfuck. "Izuna, come right here!"  She points at a spot before the other petfuck.