Vazhthugal is a story about love, not just love between a man and woman, but the love and affection within an entire family.
Kathiravan (Madhavan) is a successful entrepreneur, socially responsible and an affectionate and dutiful son. He runs Amma, a software company. Kathiravan decides to celebrate his parents' wedding anniversary in an orphanage. He is shocked to find that his friend's parents are residing there. Deeply affected by what he sees, Kathiravan arrives at the conclusion that marriage is an arrangement to separate the loving son from his affectionate parents and that old age homes are filling up with a steady stream of abandoned parents because modern married girls are brainwashing their husbands to banish their parents to old age homes. He begins to view wives as dangerous creatures who mercilessly cut off family relationships.