The Shimenawa myth has its origins from when Amaterasu Omikami (the Sun Goddess) was removed from the Ama no iwato (Cave of heaven), Ame no Futotama no Mikoto (one of the gods in Japanese mythology) strung a Shimenawa across the cave entrance to prevent the cave being entered again.
天照大神が天岩戸から引き出された際、二度と天岩戸に入れないよう太玉命が注連縄（「尻久米縄」）で戸を塞いだのが起源とされる。