While the story of Kabir Singh deviates little from its original Telugu version Arjun Reddy (2017), Arjan Bajwa, who plays Shahid Kapoor's elder brother says that he has "played a completely different character". Bajwa explains that while the love story between Kapoor and Kiara Advani remains the central plot, the film also highlights the relationship with his on-screen brother.

"Sandeep [Vanga, director] expected me to play my character differently from that in the original. In Arjun Reddy, this character is mild in his approach towards his brother. But in Kabir Singh, he is showcased as an aggressive Punjabi elder brother who is protective of his sibling. I perceived that on my own." Recounting his experience of shooting with Kapoor, the Rustom (2016) actor calls their chemistry organic. "We shot a scene where I reach his house looking for him, and scold him to come back home. The emotions came out naturally. We anticipated each other's reactions and went with our instincts. Luckily, our camaraderie has come out well in the scene."