Complex sentence: The whole plot is pretty speedy after that with Rajesh pretending as Manjeet Kumar Dana is to fall in love with Kajal (Kajal Kiran) who is actually in love with her childhood love, Sanjay.
Split into simpler sentences: The whole plot is pretty speedy after that with Rajeev pretending as Manjeet Kumar Dana to be in love with Kajal (Kajal Kiran). But, she is in love with her childhood love, Sanjay.