Kasshish mainly revolves around four main protagonists –Pia, Anand, Ratna and Aman. Pia and Anand are a happily married couple. Pia works in a travel agency while Anand is an architect working in a construction firm. Pia is the essence of the family adored by her mother-in-law, father-in-law and sister-in-law. Life is a bed of roses till one day she discovers her husband is having an affair. What shatters her further is when she discovers that the other woman is none other than her own cousin Ratna.Ratna is primarily a writer and a painter by profession living a bohemian lifestyle.Pia initially overlooks Anand's mistakes but things reach such a point that she gives him a final warning to come out of the relationship within a month's time. But Anand admits that he is unable to come out of the relationship that leads to Pia receiving the worst blow – miscarriage.Pia is devastated but finally decides to walk out. Anand's temporary exit from her life leads to Aman's permanent exit in her life.Aman is an airforce pilot with an equally painful past – his wife died leaving him with a young child to look after. Aman is a doting father and an affectionate man. What more could a woman ask for. The events that follow when Pia leaves Anand, Aman enters Pia's life and eventually when Ratna leaves Anand forms the crux of Kasshish.