Asking for a friend. Looking for a old movie he saw years ago so prob pre-2000's/90's movie.
Man buys one of those karate staffs/pole in some antique shop, goes home to sleep and gets isekai'd to past and finds himsef in past Japan/China. There he finds some old guy who proceeds to train in jungle and near bamboos or some shit, to fight and save village. That's all we got.