The 43-year-old star, who is in the role of sub-inspector Inderjeet Singh in Sujoy Ghosh's directorial venture, says his character in the sequel to the 2012 sleeper hit is special.
"'Kahaani 2' is one of the most special movies that I have done. When I saw the film what I was very pleased about was that no one has seen me in that light before. It is something very new and different for me as well. So, I was quite surprised watching myself in the film.," Arjun told PTI.
"What Sujoy is conveying through his movie is really beautiful. And he has said it in such a thrilling and entertaining manner."
The actor says he always wanted to venture into thriller genre but was waiting for a good script.
"I really wanted to do a good thriller and I think 'Kahaani 2' lends itself to being that. I'm very proud of this movie. And also very happy at the same time."
Arjun feels that he had to stand out in front of actress Vidya Balan, because she was amazing in the first part as well as Parambrata Chatterjee, who played Inspector Satyaki Sinha in the previous version.
"You always have to up your game as Vidya is a phenomenal actor. And when you have good material and good actors around you, your performance automatically becomes better.
"You also enjoy working with such people and I think that's the nicest thing for an actor and also very satisfying when you get work like that."
Arjun believes that making sequel is a "huge responsibility" as people attached to the project have to make sure that they do justice to the original film.
"It is a big challenge to make a sequel especially when you are making the sequel of a cult movie. It's a huge responsibility on the makers, producers and as well as on the actors. You have to stay true to its characters and at the same time be very true to the audience.
"Because if the audience is going to come they will come with the expectations whether you like it or not. There will be strong comparisons."
"Raajneeti" star also says he is very deliberate when it comes to selecting a film as he tries to be as divergent as possible in his movies.
"I'm very selective about my work. I try to be as different as I can in each film. And That's a very conscious decision of mine that is why I do very less work. But, every time I do something it has to be something invoked within me like 'Kahaani 2'.
"Something which allows me not just to scratch it on a surface level but also to go deep into the character.