@Eve Oh! I am fascinated by what little I know of the _yokai_, although my sole exposure to them is through children's TV *chuckles*--they are frequent minor villains in various Super Sentai series, most notable "Kakuranger", in which we're even given a narrator who explains just who all these yokai are. Indeed one of the _nurikabe_ shows up in "Kakuranger" although it's given the aspect of a maze that the traveller enters but can't leave.

And you could construct even _positive_ reasons this might happen! Perhaps the traveller would have gone to their death if they hadn't been blocked.