Jiang Ziya lived near the Weishui River about 3,000 years ago. The area was the feudal estate of Count Ji Chang. Jiang Ziya knew Ji Chang was very ambitious so he hoped to get Ji's attention.

He often went fishing at the Weishui River, but he would fish in an unusual way. He hung a straight fishhook, without bait, three feet above the water. He often said to himself, "Fish, if you don't want to live any more, come and swallow the hook yourself."

Soon his strange way of fishing was reported to Ji Chang. Ji sent a soldier to fetch him. Jiang saw the soldier coming, but ignored him. Jiang just went on with his fishing, and was saying to himself, "Fishing, fishing, no fish has been hooked. A shrimp is up to mischief." The soldier reported this back to Ji Chang, who became more interested in Jiang.

Ji sent an official to invite Jiang this time. But Jiang again ignored the invitation. He just carried on fishing, and was saying, "Fishing, fishing, the big fish has not been hooked. A small one is up to mischief."

Then Ji Chang realized Jiang may be a great talent so he went to invite Jiang himself and brought many generous gifts with him. Jiang saw his sincere desire so decided to work for him.

Jiang helped Ji Chang and his son turn over the Shang Dynasty and establish the Zhou Dynasty. Jiang was given the title of Taigong so people called him Jiang Taigong.

In this idiom, Diaoyu means "fishing," Yuanzhe means "a person willing to" and Shanggou means get hooked. Today, people use this old idiom to describe someone who willingly falls in a trap or does something regardless of the result. For example, if someone sells something at a price of 10 times its real value, and he does not care if it can be sold, his situation could be described with this idiom.