Hum Ho Gaye Aap Ke is a romantic love story story revolving around the characters Rishi, Mohan and Chandni. Rishi (Fardeen Khan) is son of billionaire Mr. Oberoi (Suresh Oberoi), who dose not believe in love or the institution of marriage and feels that he can buy anything in the world, till he realises that there is one thing that can never be bought, Love.
Mohan (Apurva Agnihotri) haild from a middle class family is a friend of Rishi and works in his office. He has his own insecurities but believes in love and is looking forward for a suitable partner. Chandni (Reema Sen) is a beautiful young sensible, middle class, confident girl who believes in love, traditional values and strict morals.
How the entry of Chandni into the lives Rishi and Mohan causes much up heaved in their inter relationships and how she brings about a change in them with her convictions is what the film is about.