Vagai is centered on the love story between a young guy (Bala), son of Village’s great man (Sai Kumar) and a beautiful girl (Visaka), daughter of Village Postmaster (Thalaivasal Vijay). Both of them have fallen in much more adhering relationship with such a bonding that they can’t live away. But misery strikes through Bala’s dad Sai Kumar who fiercely objects their affair and indeed urges his henchmen to kill the girl. Now Bala and Visaka run for their lives, but cannot move further. When Bala interprets that if they catch hold of his ladylove, they’ll kill her. So, both of them consume poison and go separated getting into different trains moving at opposite directions.