Hojojutsu
Hojojutsu (捕縄術) is the traditional Japanese martial art of restraining prisoners using knotted ropes. They were also used as a form of torture.
These techniques are still taught in Japan for police work and are commonly seen in traditional ju-jutsu systems.
They have also been adapted in less brutal forms for sexual bondage in the form of kinbaku, (also known as nawa shibari, literally "rope tying").