Chancing upon a life as a drifter and a con man, Sameer Khanate (Mashhoor Amrohi) makes his way to Singapore and lands a job working as a 'Recovery agent' for Gary Rosario (Jackie Shroff), an underground racketeer of night clubs.
Earning his livelihood by masquerading and cheating people of their money, Sameer's life takes a tumble when his own brother finds himself in need of financial help. With his Boss - Gary Rosario refusing to help him out, Sameer is left with no viable option. He comes up with a vicious plan of kidnapping the daughter of a multimillionaire super star actor, Gyaneshwar Singh (Shehzad Khan) in order to solve his financial crunch.
In his quest to relieve himself of his unavoidable misery, he promises Esha a world of dreams and leads her into believing that they are soul mates. What Sameer doesn't realize is that destiny has different plans for him, as he succumbs to the temptation of Gyaneshwar Singh's daughter Esha's (Vishakha Singh) beauty, and falls head over heels for her. He takes her off to a romantic weekend on Sentosa Island, with the dual motive of spending some quality time with his newfound love and getting her away from her dad and asking him for a ransom. Seeing a beautiful possibility of living a life full of happiness with Sameer, Esha also agrees to elope with Sameer.
The repercussions of this are tremendous and never thought of, as Gyaneshwar Singh is led to believe (by Sameer and his accomplice/best friend) that she has been kidnapped. This revelation forces him to make one phone call to his best friend, Gary Rosario, who promises Gyaneshwar that his daughter will be back safe and sound and that he will appoint his best man to rescue Esha. The man for the job is none other than Sameer Khanna (the guy who kidnapped her in the first place).
Further complications arise when Sameer gets involved in a drug deal, and in the process loses Esha to a gang of drug lords Dabar (Mukesh Rishi) and Pran Panwara (Kiran Kumar) who ask Sameer to comply with their horrendous demands in return for her life. Sameer now has to get Esha from the unscrupulous hands of Dabar and Pran Panwara while pretending to never ever have met Esha for his life to be spared in front of Gary Rosario and make all well with his finances. There is just one problem, circumstances and fate have revealed the reality of Sameer in front of Esha and she has no plans of letting him off the hook so easily, even if it means letting everyone think she's dead. Esha wants payback with Sameer while the whole world is gunning him down with Esha's presumed death. A friendship begging for generosity, a love screaming from betrayal and pride waiting to be awakened, Hum Sey Hai Jahaan is a rollercoaster ride that will jolt your senses to laughter and entertainment and will leave you asking for more...