Aaj shaadi ke saat phere lene se pehle… main yeh pratigya karta hoon ki main umr bhar Urmi ki dekhbal karoonga aur us par kabhi koi aanch nahi aane doonga…” This is the vow Aadesh takes on his wedding day to Manali. Will Aadesh keep up to Aathvaan Vachan

Urmi is a problem child and a huge worry to her parents, a burden to her brother, a menace to her sister-in-law and everyone around... except her sister Manali. Manali and Urmi are sisters who seem to be joined by an umbilical cord… a cord that cannot be severed off. It is this bond that forced Manali not to pursue a career and refuse marriage proposals… her priority is Urmi and she takes care of her day-to-day needs. This unusual bond only confirms that they are there for each other.

In a society like ours where marriage means marrying not only the person but his family also, will Urmi's mental status be a hindrance in Manali's happiness? The simple narrative takes an unusual twist when Aadesh meets Manali marries her and promises to look after Urmi. Aadesh turns out to be a man in this situation as he decides to marry Manali.The family is shocked with Aadesh's decision but he goes a step further by renewing his promise to Manali, while taking his marriage vows. While life for Urmi continues to be fun and games at her sister's sasural, fate has other plans for her. Manali dies leaving Urmi in Aadesh's care. Urmi and Aadesh find themselves in an unusual situation. How they face life is what Aathvaan Vachan... saath vachano se badkar is all about. What would Urmi's fate be when she loses her soul support her sister? Will Aadesh be able to live upto his promise to Manali?