Her entire life, Shuri spent every waking second in a treacherous swamp where danger lurked behind every corner. Her life was quite literally teetering precariously at the edge of a sharpened blade. Through repeated failures and stumbles, Shuri's instincts became extremely sensitive to encroaching danger.
Ever since she hitchhiked with the man whose name she deigned not to learn, her instincts were blaring "DANGER" ceaselessly. However, Shuri suppressed it and wrote it off as uneasiness wrought by the sudden change in scenery. After all, moving from an environment where one needs to be constantly on the lookout for death-inducing trouble, to another where a mistake didn't always end up with death or serious maiming can be seriously disorienting. Thus, Shuri affiliated the growing sense of foreboding gnawing at her as the result of an idle mind cooking up all kinds of trouble.