Hojōjutsu (捕縄術) is the science of arresting a prisoner and binding them with rope. The rope in question was usually hemp or jute, but sometimes (more commonly later in history) cotton or even silk.
Classically, during the Sengoku-period (1467 – 1603), a number of soldiers on the battlefield would assail the prisoner and pin him down while one applied the rope in a preconfigured pattern. Much later, in the Edō-period (1603 – 1868) where single combat and small scale conflict replaced large scale, methods for fighting and grappling with shorter lengths of string, hayanawa (quick rope; 早縄) were developed for apprehending the culprit and restraining them while the longer hon’nawa (main rope; 本縄) was applied afterwards for a more appropriate tie.
Many of the intricate ties and patterns that we’ve come to recognize in hojōjutsu were invented, and some might say discovered, for the purpose of identifying the type, context and severity of crime. Other such variables include the prisoners gender, region of Japan, social cast, disabilities, and so on. The reasons for these were numerous, and only a small ratio of these ties were standardized enough to be recognized outside of the local region.
There were even ties specific to certain martial ryūha (family traditions; 流派), where the pioneers of each tradition would imbue their grasp of the physical technique, concepts, complexities, and even spiritual ideologies in to the practice of ideologies. Some of these traditions were exclusively hojojutsu practices, while others were sōgō bujutsu (composite martial sciences; 綜合武術) and mingled into a full curriculum of other practices such as swordsmanship and grappling.
there is also the tying involved in practices of Japanese torture (seme; 責め), where the detainee would be bound in particular ways to restrain him as well as expose the maximum amount of bare skin for striking and inflicting pain. Also the practice of tsubaku (suspension tie; 吊縛), where the captive would be tied with his arms behind his back, and hung by the arms and torso for prolonged periods of time.
There is always pioneers such as Taiso Yoshitoshi and Seiu Itō, and modern contemporaries such as Osada Steve and Hajime Kinoko (as well as many others) who have developed the fields into erotic rope bondage, also known as shibari (tying; 縛り), kinbaku (tight binding; 緊縛), and several other names. These practices tend to be more popular than that of hojōjutsu, and because of being refined and escalated to the status of artistic expression, they are becoming less about eroticism and more about tantric exploration and aesthetic composition.