Sister-In-Law Is at Home!

Pandit Ji predicts a change in the life of Manmohan Tiwari, an undergarment businessman. Vibhuti Mishra, a policy agent, and his wife Anita Mishra, a grooming teacher, are about to relocate to Tiwari's locality. Manmohan gets an undergarment order of INR 5 lakhs from Mr Agarwal, who is about to visit him with his wife. Manmohan and his housewife Angoori are excited. The Mishras mistake the Tiwari house for theirs. The Tiwaris mistake the Mishras for the Agarwals. A misunderstanding ensues.

As Vibhuti dreams about romancing Angoori, Anita wakes him up and asks him to get milk. On his way, he sees Angoori praying in the verandah and stops to talk. Manmohan wants to bathe, but the water supply has stopped. So, Manmohan decides to bathe at Anita's home. Vibhuti rushes to use the loo but finds it occupied by Manmohan. Manmohan pretends to fall in the bathroom, and a doctor is called. Manmohan asks the doctor to lie that his hip is fractured and that he should not be moved at all.

Dr Gupta leaves and thinks about Manmohan's plan. Laddoo, Manmohan's younger brother who can hear what people are thinking, reads his mind. Laddoo goes to Manmohan and confronts him. Manmohan bribes him with new shoes. Saxena, a neighbour, bumps into Angoori and apologises. Vibhuti slaps Saxena. Anita serves turmeric milk to Manmohan. Vibhuti cooks, and the Tiwaris and the Mishras have dinner together. Anita goes with Angoori to sleep at Tiwari's home. Saxena decides to teach Vibhuti a lesson.

Vibhuti can't sleep with Manmohan as he snores. Vibhuti eventually goes to sleep in the living room. Saxena enters Vibhuti's bedroom and beats up Manmohan under the blanket thinking that he is Vibhuti. When Manmohan takes off the blanket, Saxena has gone, and there is no one. The next day, Manmohan asks Vibhuti if he has vengeful foes. Manmohan decides to go back to his house but is unable to. Saxena overhears Vibhuti and Angoori's conversation and finds out that it was Manmohan in the bedroom.

Manmohan asks Vibhuti to sleep in the bedroom and he sleeps in the living room. Saxena enters Vibhuti's home and beats up Manmohan thinking that he is Vibhuti. Manmohan shouts, and Vibhuti comes with a stick. Manmohan thinks that Vibhuti is hitting him. Anita shouts at Vibhuti, but Angoori thanks him for curing Manmohan. Angoori sees Manmohan following Anita and confronts him. Angoori wonders what makes Anita special. Ammaji, Manmohan's mother, explains that she needs to groom herself.

As Anita and Vibhuti try to catch a rat, Manmohan enters. Vibhuti throws a fork on the rat, but it hits Manmohan. Manmohan offers to get rid of the rat without harming it. He gets a snake charmer's instrument to lure the rat, but it instead attracts a snake. Laddoo and Pandit Ji say that this snake's bite could turn humans into serpentine creatures. Manmohan finds Angoori applying ointment on her skin. He notices that her eye colour has changed and assumes that she has become a serpentine woman.