Maattrraan is about conjoined twins, and one of the twins will have Karthi's voice while the other will have Suriya's.
Many producers have been trying to cast the real-life brothers together in a film, but as a part of their strategy the brothers have refused to do a film, or even a photo-shoot, together.
Both Suriya and Karthi have a market in Telugu. Karthi, in fact, after becoming a star learned Telugu and is now adept with the language.
Suriya has dubbed in Telugu for the first time with Brothers.