Happy Hardy And Heer is a musical romantic comedy set in London where Harshvardhan Bhatt and Harpreet Singh Lamba (both characters played by Himesh Reshammiya) fall for Heer Randhawa (Sonia Mann). Happy and Heer were childhood friends in India before Heer's family migrated to London. On turning young Happy tries to relocate himself to London on the pretext of finding a job and getting Heer's attention but Heer is engaged to Hardy who is a successful businessman in London. This sets the stage for both to compete with each other on winning Heer's heart.