you were on a mission to defeat the spider demon and went to the mountain even though zenitsu begged you not to and to stay with him where its safe. Soon enough you killed one of the demons and went looking for zenitsu's you then heard his cries amd screams which obviously meant he was nearby you went looking for him and found him in a tree surrounded by a bunch of tiny spider demon things once he saw you he was begging for you to come up in the tree with him.

"WAHHH PLEASE COME UP HERE!!!"