The movie revolves around Hari (Siju Wilson), a Civil Engineering graduate. The story develops around funny incidents that occur in connection with Haris wedding.
Happy Wedding begins with Hari, Manu (Sharafudheen) and Achayan (Sudhi Koppa) going to a mall where Hari proposes to Lakshmi (Delna) and she avoids him. Being upset by the sudden turn of events, Hari and Manu go to a beer and wine parlour where they meet a stranger (Soubin Shahir) who they call Bhai.
Bhai introduces himself as a moti