Aaru in this movie Aarumugam, nicknamed Aaru (Surya Sivakumar), is a thug and dealmaker with a band of boys handpicked from the slums of Chennai. Aaru’s mentor Viswanathan (Ashish Vidyarthi) protects him, because Aaru gives him the violent undercover he needs. When Vishwanthan declares war on his bitter rival Reddy (Jaiparakash Reddy), Aaru assists him. But Vishwanthan betrays him, resulting in the deaths of Aaru's subordinates. Aaru thus realizes Viswanathan's true, evil nature and vows to destroy his power. There is also a subplot involving Aaru's romance with the college student Maha (Trisha Krishnan).