Filmmaker Rakesh Roshan says the idea of making "Koi... Mil Gaya", a sci-fi movie for children and family audiences, came to him from his granddaughter who used to be the fan of an animation show featuring an alien.

"Koi... Mil Gaya" revolved around a developmentally disabled young man Rohit Mehra (Hrithik Roshan) and his chance encounter with an alien called Jaadoo, who gives him new powers. The movie released on August 8, 2003 and became a box office success.

"The idea of making 'Koi... Mil Gaya' struck me one day when I was observing my granddaughter Suranika (Sunaina Roshan's daughter) watching a cartoon that featured an alien. I was instantly intrigued and asked her out of curiosity if she understood the concept and she explained the story to me. I was surprised that a kid her age not only understood what an alien was but also seemed entertained by the sci-fi concept," the director told PTI.

"Koi... Mil Gaya", also starring Preity Zinta and Rekha in pivotal roles, was intended to be a family entertainer and the vision, Rakesh Roshan said, was to create a sci-fi story which was easy to understand.

"It was a sci-fi movie with an alien, which was a very novel concept at that time in India," he added.

Hrithik as Rohit played a man with a mind of a nine-year-old, who has his own circle of friends 'The super six'. Actors Hansika Motwani, Omkar Purohit, Jai Choksi, Mohit Makkad and Pranita Bishnoi played Rohit's friends.

The filmmaker said he had full faith in Hrithik's talent, but was blown away when his superstar son exceeded the expectations.

"The task was that he had to play this role alongside five other kids, so he had to fit in and not play the part as a solo hero. I gave him this opportunity because I believed in his talent and I had full faith that he would do justice to the part... He did his research, and got into the skin of his character and camouflaged in between all the kids, that was completely mind blowing. It was a filmmaker's delight to watch an actor deliver beyond imagination," the 73-year-old actor-director recalled fondly.

The most challenging part in the movie was to create the alien, Rakesh Roshan said. He contacted Australian artists James Callner and Lara Denman with the film's concept.

"I was certain that I wanted an alien that the children would not be scared off, rather someone who would be seen as a friendly alien. So, I shared the concept of an alien who was of the same height as the children and someone with very expressive eyes, as Jaadoo primarily communicates through his eyes.

"Basis the brief, they shared a sketch of Jaadoo and it was in that instant I knew 'Jaadoo Mil Gaya' (we have found Jaadoo). All these little little things together added up to the connect 'Koi... Mil Gaya' has with the kids and has been garnering love since the last 20 years," the director added.

Rakesh Roshan followed up "Koi... Mil Gaya" with a sequel "Krissh" (2006) and turned it into a franchise with "Krrish 3" (2013).

It was "The Lord of the Rings" movie series that inspired the director to turn "Koi... Mil Gaya" into a film franchise.

"I had the idea of taking forward the story of 'Koi... Mil Gaya' as the ending had potential. I thought of a one line concept and discussed it with Hrithik and he was overwhelmed with joy upon hearing it." Introducing a superhero film to the Indian audience was a tricky job, said Roshan. The director recalled how important it was to keep the film high on emotions for the Indian audiences.

"It was the first time we were to introduce a superhero film to the Indian audience. We did not have reference points from past Indian films. While there were international superhero films being made at that time, the Indian audience needed films that were high on emotions too. The fact that 'Krrish' became a blockbuster was because it was a superhero film with a very human heart at its core, full of emotions," he added. Reports of "Krrish 4" have been doing the rounds for a while.

The director did not comment on the reports but said he would like to carry forward the franchise both "as a story and as a visual entertainer".

"Since its inception, 'Koi... Mil Gaya' franchise has been an ambitious idea. We've always upped the scale and the stakes. My ambition is high to carry forward 'Krrish', both as a story and as a visual entertainer. When we made Koi... Mil Gaya there was minimal use of VFX as it was a new concept, only the spaceship scene had VFX, rest was groundwork and a lot of hard work to create from scratch. Now with the technology of VFX at its peak, we have set higher standards and are dreaming bigger," he said.

"Koi... Mil Gaya" was based on a story by Roshan, who also co-wrote the screenplay with Honey Irani, Sachin Bhowmick and Robin Bhatt. Javed Siddiqui was the dialogue writer.

Music was composed by Rajesh Roshan.

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