Song Sao Fish, also known as West Lake Vinegar Fish, is a traditional dish in Hangzhou. According to legend, in the Song Dynasty, the Song brothers lived by the West Lake in Hangzhou, who made a living by fishing. Once, the local villain Zhao Daguan was visiting the lake and saw Mrs. Song's beauty, and he immediately wanted to occupy her. He used deceit to murder her husband, and also wanted to harm her brother-in-law. Song's sister-in-law persuaded her uncle to flee, and before leaving, she cooked a grass carp with sweet and sour food, which contained a profound meaning: if one day you live a good life, don't forget the bitterness of the past and the suffering of the people. Sister-in-law Song also fled to other places. Later, his brother-in-law gained fame and became an official. By chance, he ate the tender meat, sweet and sour vinegar fish, so he searched around and finally found his reclusive sister-in-law. He resolutely resigned from his official position, returned to life as a fisherman, and supported his sister-in-law. "West Lake Vinegar Fish" has been passed down together with this story.