Satyender (Shashi Kapoor) works for Chaudhry Kripal Singh (Dr. Shree Ram Lagoo). Satyender is an ambitious person. He manages to go abroad to earn wealth and make fortune for his family that is his wife Suman (Tanuja) and little son Rajeev (Raaj Tandon).
Time passes, Satyender becomes a rich man and starts his own industries at his native place Mangalore. Rajeev is a grown-up young man. He meets Rohini (Rubeena), the grand-daughter of Chaudhry Kripal Singh. They become friendly. Kripal Singh is an egoistic and he does not like the idea of Satyender, who was his clerk, coming up equal to his status in society.
One day, in a party, Satyender asks Kripal Singh for the hand of his grand-daughter for his son Rajeev. Kripal Singh bursts out and insults Satyender in front of all the guests. Both the families become enemies and Rajeev decides to tame Rohini in order to teach her a lesson. But fate has something else in store for them.
Both Rohini and Rajeev are kidnapped by Manga's (Ranjeet's) gang. Despite dangerous situation, both fall in love. Rajeev succeeds in killing the gangsters —comes back to the society — society makes him a hero but looks down at Rohini thinking that she has been raped.
Now, how Rajeev fights the society for Rohini is the culmination of "EK MAIN AUR EK TU".
[from the official press booklet]