They are as dissimilar as chalk and cheese. Precisely why director Anjan Dutta has decided to cast sisters Raima and Riya Sen in an English-language film tentatively entitled "The Bong Connection".

"But we aren't cast as sisters," says Raima, the more sober of the two Sen siblings.

"We don't even meet in the film, not even like my grandmom Suchitra Sen's and Vyjayanthimala's vehicles running into one another in 'Devdas'. We're in two completely different sections of the film. My part of the story is set in Kolkata. I'm the modern yet traditional Bengali girl. My sister plays the hip NRI in the US. We have no scenes together. Her story will be shot in the US, mine in Kolkata."

Anjan Dutta has designed it as the first Bengali crossover film targeted for the overseas market.

This isn't the first film to bring siblings together. Shamita Shetty and elder sister Shilpa were recently seen together in Deepak Tijori's "Fareb", again not as sisters.

Said Shilpa: "Though I'd love to be my sister's sister on screen, I think it would be slightly awkward to play real-life roles. It's far more challenging to come together and play against one another, as rivals in love as we did in 'Fareb'."

In Dharmesh Darshan's "Mela", Aamir Khan agreed to co-star with his sibling Faizal. He played Veeru and Faizal played Jai from "Sholay", but with no real success.

Real-life siblings Rahul and Akshaye Khanna crossed each other briefly in Deepa Mehta's "Bollywood/Hollywood".

Salman Khan and sibling Sohail have become quite a pair. They were recently seen together in David Dhawan's "Maine Pyar Kyun Kiya" and will be together again in Rumi Jaffrey's "God Tussi Great Ho". Earlier it was Salman and Arbaaz in "Pyar Kiya To Darna Kya" and "Hello Brother".

Feroz and younger brother Sanjay Khan came together in two films, "Mela" and "Upasna". In both, they fought for the love of the same woman, Mumtaz.

Earlier still, it was real-life brothers Dilip Kumar and Nasir Khan playing siblings in Nitin Bose's "Ganga-Jumna". This is the only film starring siblings that has clicked in a big way.

No wonder Karisma and Kareena Kapoor have constantly said no to all offers to act together.