What happens when write goes wrong and wrong goes write? It leads to a comedy of errors and a series of misunderstandings, which is exactly the tale of Shimla Mirch. Avi (Rajkummar Rao) is a happy-go-lucky young man from an affluent family in Delhi. On one of his visits to Shimla, he falls in love with Naina (Rakul Preet Singh) who lives with her mother. Avi finds it hard to express his feelings to Naina as he tries to pen down through a letter but unfortunately, it falls into Naina’s mother’s hand. Thus, begins a journey of misunderstandings as Naina tries to get her mother married to Avi.