Kyaa Kool Hai Hum

Rahul is earnest, hardworking, and loyal, often finding himself pulled into Karan's reckless schemes. After eviction, he and Karan improvise a tenuous, patchwork life while pursuing romance, all while facing the danger of a police investigation. He is quick to trust others and deeply values his bond with Urmila, making his innocence central to the film's tension.

Karan is bold, flashy and always chasing the next thrill. His quick-witted schemes lead to comic misadventures, including a car theft that lands him in trouble. His romance with Kiran and his evolving understanding of love push him toward more responsible choices, especially as identity and trust come into play.

Undercover and newly transformed by makeup and disguise, Urmila is tasked with Rahul's pursuit but grows attached to him. Her undercover mission becomes tangled with genuine feelings, complicating police work and romance alike. She embodies the tension between duty and desire as the investigation unfolds.

Rekha is a psychologist who links the romantic and investigative threads of the plot. She plays a pivotal role in unmasking the truth and revealing that Kiran is actually connected to her, adding layers of mistaken identity to the story. Her involvement drives the resolution as love and justice converge.

A psychologist who supports the investigation, Dr. Screwvala adds a clinical perspective to the pursuit of the killer. His interventions help steer the melee of miscommunications toward clarity and truth. He serves as a professional anchor amid the film's chaos.

Kiran is Rekha's brother and the boss's ex, a connection that complicates romantic feelings for Karan. The character's mistaken identity and family ties intensify the plot's twists, especially in the wedding climax. Their relationships seed the narrative's emotional confusion.

The real killer, Uma Shankar Tripathi, is revealed as the true culprit, closing the mystery and vindicating Rahul. The pursuit of justice pivots on exposing this villain and arresting him, ending the immediate threat. Rajpal Yadav portrays the menacing antagonist behind the chaos.

Shoma Anand's character is a supporting presence in the medical/psychological circles surrounding the investigation. She contributes to the film's network of relationships that enrich the comedy and suspense.

Jay Sean appears as himself in a light cameo, adding a pop-cultural moment to the film's playful mood and celebrity cameos.