Prabhu Selvaraj (Tamil version)/Adi Tomar (Hindi version) (R. Madhavan) is a failed boxer who, despite being very talented, falls victim to the dirty politics in the boxing association. Ten years later, he is a coach for the women’s boxing teams but is extremely angry and frustrated with the partiality in selection. Due to his rift with the association head Dev Khatri (Zakir Hussain), he is falsely charged with sexual harassment and transferred to Chennai. Despite the very poor infrastructure, Prabhu/Adi manages to find talent in a roadside fish seller Madhi (Ritika Singh), who he notices while she is thrashing the judges during her sister’s tournament.
Ignoring Madhi’s elder sister Lakshmi (Mumtaz Sorcar) who has been boxing for 8 years, Prabhu offers to train Madhi for a few hours daily. But the two don’t get along due to Prabhu’s/Adi’s ruthless training methods and Madhi’s aggressive nature. As a result, Madhi intentionally loses a local match. Prabhu later asks Luxmi and Madhi’s parents, Saamikannu (Kaali Venkat) and Damayanthi (Baljinder Kaur), to send them to stay in hostel with him so their daughters can work hard on training. Madhi misunderstands him, but later regrets when she finds out that Prabhu has sold his bike to buy new training equipment for her. Madhi then dedicatedly starts training with Prabhu and develops feelings for him. On the day of a qualifying match, she reveals her feelings to Prabhu and he promptly rejects her. During the warm-up before the match, a now jealous Luxmi injures Madhi’s hand causing Madhi to lose. Angry, Prabhu thinks that Madhi lost intentionally again and throws her out of training camp.
Dev takes advantage of the situation by calling Madhi to Delhi for a cultural exchange tournament and makes her fight with a heavy weight Russian boxer, who knocks out Madhi in a few seconds. A demotivated Madhi is then approached by Dev with an indecent proposal, to which she reacts by injuring him. Dev takes revenge by getting her arrested on false theft charges.
Prabhu comes to the rescue and bails her out. He later takes Madhi to Delhi to get her a wild-card entry into the World Boxing Championship. Many people in the association, including Lakshmi, accuse Madhi of offering sexual favours to Prabhu. Ignoring all the accusations Madhi works hard and goes on to win the semifinal. On the day of finals, Dev removes Madhi’s name from the list and asks Prabhu to resign immediately if he wants to see Madhi in the final, with the same Russian boxer who knocked her out in Delhi. Madhi gets to fight in the final round but is dejected after learning about Prabhu’s resignation. She keeps losing points in the early rounds and gets badly injured before Prabhu shows up at the stadium and indicates her to attack her opponent’s arms to make her weak. Madhi follows the game plan and knocks out the opponent with seconds to go in the final round. Dev quickly jumps into the ring to take the credit for training Madhi but she punches him and runs to Prabhu. Madhi and Prabhu hug each other, showing emotional reunion of a coach and student.