An idiom used to describe someone who does something of their own free will or falls into a trap willingly; part of a two-part saying where the second half is [[愿者上钩|願者上鉤|yuan4 zhe3 shang4 gou1]], meaning "those who are willing will bite the hook".

To do something of one's own free will despite the risks; used to describe a situation where someone willingly falls into a trap or takes an action knowing the consequences. This idiom refers to the legend of the sage [[姜子牙|姜子牙|jiang1 zi3 ya2]] fishing with a straight hook above the water, waiting for the fish to choose to be caught.