Jizai musubi 自在結び
The Japanese name for the taut-line hitch, an adjustable hitch that can be slid along a line yet grips once it is loaded.
Shibari Study’s glossary lists jizai musubi (自在結び) as the taut-line hitch, a hitch that slides along a rope but holds once it takes load. Japanese Wikipedia gives the same equivalence and the alternative name harizuna musubi, guy-rope knot, after its common use for fixing tent guy lines. English Wikipedia describes the taut-line hitch as an adjustable loop for lines under tension, also used by arborists and to secure loads on vehicles. Shibari Study does not say where in rope bondage the hitch is typically used.