Tumm Se Tumm Tak follows Anu Sharma, a 20-year-old middle-class girl from Chandni Chowk, Delhi, and Aryavardhan "Arya", a 46-year-old successful industrialist heading the Vardhan Group of Industries. Anu's father works at a local store that sells Rajnandini Sarees, a brand owned by Arya's company.
Their lives intersect, when Arya's bicycle breaks down on the way to the Annual Function of K.C. College, where he is the chief guest and Anu is invited to give a speech. Sharing an auto-rickshaw unknowingly, Anu is initially unaware of Arya's identity. Despite an awkward first meeting and a public mishap, during her speech, Arya is impressed, by Anu's sincerity and offers her a job at his company.
As their relationship develops, Anu is pushed toward an arranged marriage with Bipin, orchestrated by the manipulative Raghu, who seeks personal gain. Arya quietly works behind the scenes to stop the marriage, by uncovering Raghu's hidden motives and exposing him using a new company policy that, reveals Raghu's conflict of interest.
Anu and Arya navigate challenges posed, by their differing social backgrounds and the opposition they face from Arya's confidant Jhende and Arya's assistant, Meera.
