Shimenawa 注連縄
A Shinto rope of straw or hemp hung at shrines, sacred trees and rocks, and at house entrances at New Year, to mark off a pure or sacred space.
A shimenawa, “enclosing rope,” is a Shinto ritual rope that separates a sacred or pure space from its surroundings. Kotobank lists the alternative spellings 標縄 and 七五三縄 and describes it at shrine halls and torii gates as a sign that a deity is present, and at house entrances at New Year to keep misfortune out. It notes that the rope is twisted from straw in the left-hand direction, with paper streamers (shide) hung between straw tassels. English Wikipedia adds that hemp was the traditional material until a 1948 ban on hemp growing made rice straw the norm, that shimenawa also mark trees and rocks thought to house spirits, and that a sumo yokozuna wears one in his ring-entering ceremony. Kotobank adds that at root it was a folk custom for marking boundaries rather than a matter of faith or law. Neither source mentions bondage.