Shi En was the son of the chief jailer of the prison in Mengzhou. He stood at above 6 feet, had a fair and handsome face, along with a beard. He was nicknamed 'Golden-eyed tiger cub' (金眼彪).
Once, Wu Song was being exiled to the prison in Mengzhou. Shi En respected Wu Song as a hero and managed to persuade his father to spare Wu Song from a punishment of 100 strokes of the paddle. According to the law, every new prisoner has to endure 100 strokes of the paddle upon entering the prison. But, Shi En brought Wu Song to a clean cell and treated him with good food and wine everyday. Wu Song was grateful towards Shi En and wanted to repay Shi En for his kindness. Shi En told him that he had once owned a restaurant, but one day a hooligan named Jiang Zhong came and beat up Shi En and took over his restaurant. Wu Song promised to help Shi En get back his restaurant.