Kalavani is romantic comedy film. Two villages in Thanjavur area are always at loggerheads with each other and it spills even to T20 cricket match between kids from both the villages. Arikki @ Arivazhagan (Vimal) is a wayward son of Lakshmi (Saranya Ponvannan) who is in awe at the same time fears him. Her husband Ramasamy (Ilavarasu) is away in Dubai and a large part of the money he sends home is taken away by Arikki using extortionist methods like threatening to break the TV set at home. He yet to pass his 12th standard spends his time in bars with his friends, teases girls and asks them to profess their love for him, and gets into brawls after conning others. He meets Maheshwari (Oviya) and wants her to declare her love for him, which she finally confesses. Her brother Ilango (Thirumurugan) is a tough guy who has an axe to grind against Arikki and his gang, which leads to the twist in the climax.