That day, Ding Wu and his good friend Li Guo went on a business trip to Shanghai together. Li Guo, who had always regarded women as worthless, kept boasting about how he could easily lure women into falling for him, only to cruelly abandon them afterwards. However, Ding Wu believed that his beloved wife, Pang Na, would never do such a thing. Li Guo said that all women were the same in this regard. In order to prove himself right, Ding Wu turned back to Beijing without even leaving the Shanghai airport, and made a bet with Li Guo: there are chaste women, and Pang Na is one of them.