We have already reported that ace director Mani Ratnam has asked Karthi to shed weight for their next venture. After completing Kashmora, Karthi will begin a strict diet regime to get fitter. In a recent interview, Karthi has revealed that working with Mani Ratnam is like going back to school and he would like to have a guru-sishya relationship with his master, similar to that of Kamal-KB.