After co-producing Kaal, a movie very unlike him, Karan Johar is back to the theme he does best: relationships.

"I've got Veer-Zaara and Bunty-Babli in my new film," chuckles Karan Johar, referring to the cast of his directorial venture Kabhi Alvida Na Kehna.

"It's got Shah Rukh Khan, Preity Zinta, Abhishek Bachchan, Rani Mukerji and Amitabh Bachchan. Believe me, that (Big B's) was the only piece of casting in the film that's irreplaceable. If I didn't get Mr Bachchan for the role that I have in mind, I wouldn't have been able to make this film. It's a role that rocks!" says Johar.

"As for Abhishek, I think his presence on the posters would add curiosity value to the project. This is the first time he's working with me. I'm really happy to have him in my film."

The enthusiasm level for his new film has been rising over the months, as Karan has been struggling to put together the script. The director says Kabhi Alvida Na Kehna is his most mature and in-depth take on human relationships.

"It hasn't been easy," he says. "In terms of characters, this is untrodden territory for me. But the important thing this time is not the stars that I've signed. It does not matter if Shah Rukh has played Veer or Rani is Babli. Once I wrote the script, they became the characters that were playing in my mind. Shah Rukh Khan in Swades and Mr Bachchan in Black were Mohan Bhargav and Debraj Sahay. The same will hopefully happen to them in my film.

"Kabhi Alvida is one film that is not about getting the stars together. I admit K3G was guilty of that. But in my new film, the stars will cease to be stars. The characters will take over completely. There're no major confrontation scenes, no drama, no dips and highs..."

But Karan shoots down rumours that Kabhi Alvida is going to be a departure from the 'Karan Johar style.'

"Hello? I've tried to make every film different from the rest. If they still carry my stamp, what can I do? And why should I try to get away from it?" he asks.

"Not that I'm comparing myself to him, but Guru Dutt's films bore his stamp even when they were as dissimilar as Sahib Bibi Aur Ghulam and Pyasa. And my favourite director Sanjay Leela Bhansali makes different films each time. Yet they bear his stamp. So I won't say I'm trying to get away from my style in Kabhi Alvida. So yes, in terms of look, it will be as glossy and glamourous as my earlier works.

"I hate it when I'm asked if my films are made for NRI (non-resident Indian) audiences. I make films for Indians everywhere from Bihar to Birmingham. Kabhi Alvida will be no exception. But it will be much more of an intimate study of human relationships than any of my films," he says.

Ask Karan how he chose the film's title and he answers, "My film had to be called Kabhi Alvida Na Kehna. It goes with the theme of human relationships set within a contemporary milieu. But to my dismay, I discovered that the title belonged to Aroona Iraniji. She had finalised a television serial by that title. "

"With trembling hands, I dialled her number to submit my request. She was very categorical. 'Beta, everything costs. So what are you willing to give me as compensation?' I told her she could have whatever she wanted, if the title is mine. She said, 'You can have it on one condition. You have to give me a hug and a kiss when we meet.' I was completely bowled over by her goodness. I guess I'm reaping the benefits of the goodwill that my father (the late Yash Johar) sowed."

Karan had planned to shoot in Australia but the location has changed. The film will start shooting in September, and Karan hopes to wrap up by the yearend.