In Unnai Thedi Raghu, studying in Australia, goes to New Zealand with a friend and runs into Malavika. They start off having petty fights but end up falling in love. But circumstances force them to separate without exchanging any information about each other. Back home, Ajith makes friends with Karan and chances upon his family photograph which surprisingly includes his mother, who as far as he knew had no relations. But on questioning, his mother reveals that she was part of a large family.