Bobby (Mohanlal), orphaned at a young age, is brought up as his own son by his uncle, Retd. I.G Matthews (Thilakan). He is betrothed to Chackochan's (K. P. Ummer) daughter, Tina (Anju (actress)). However, his old flame from college, Nina (Shobhana), turns up with a toddler allegedly fathered by Bobby. He denies this vehemently and goes to great lengths to prove her wrong, whilst keeping this under wraps from his fiancée. Despite a slew of hilarious events involving Unnunni (Jagathi Sreekumar) and his paranoia about his wife Daisy (Subhashini) seeming to have an illicit affair with Bobby, Bobby is unable to prove his claims that the child is not a result of his relationship with Nina in the past. In the meantime, Nina develops a strong bond among all the members in Bobby's family, except Bobby himself.