Mei Yeung-sun (Tang Kiu-lap) is a man of letters who is less than thrilled with his sex life with his comely young wife Ti Yuk-xiang (Cheng Yuen-man). Yet when Mei uncovers the family sex manual, their physical relationship improves considerably. So successful is the transformation that the two spend all of their time in the sack, much to the consternation of the girl's father. Later, Mei leaves home supposedly to become an official in the big city. In fact, Mei really plans to troll around the countryside and have sex with as many women as possible. Thanks to the advice of master thief Tsoi Kwun-lung, Mei visits a noted doctor and leaves the place with a massive newly installed penis. Brimming with cocksure confidence, he soon seduces lonely housewife Yim-fong. Her thuggish husband Kuan Low-si (Sun Chien) soon gets his revenge.