In shibari this pole is often a bamboo. Bou shibari is named after a nō 能 (or nōgaku 農学) theatre play where 2 servants are tied during the absence of their master because of their habit to steal sake. The 2 servants are tied to a pole behind their back (or one of them) and all the humour is based on how these 2 servants will be able to drink sake while being tied.
