Mann Mayal depicts the story of Manahil (Maya Ali) and Salahuddin (Hamza Ali Abbasi), who are neighbors and Salahuddin's sister Rabia (Aiman Khan) is a friend of Manahil. Salahuddin is ambitious for studies but is however asked by Manahil's father to give tuition to Manahil because of her low grades. Both fell in love but Salahuddin refuse to marry Manahil due to their social-class status and due to fear of rejection from her family. Manahil's parents accept the proposal of Mikaeel who is unknown to Manahil's family is a spoiled-habitual person. Salahuddin says last goodbyes to Manahil before her marriage only to end up in allegation that he took her, he then settled things out and left for karachi to work at his friend Iftis' (Vasay Chaudhry) firm, where he met Ifti's father Rehman (Talat Hussain) who is dying of cancer and is treated poorly by his daughter in law Cockie (Arjumand Rahim) and housekeeper Jamil (Saleem Mairaj). Salahuddin and Rehman develop a close bond and they confides in each other.