"A man named Saajan Fernandez, a Christian who works as an accountant in a govt. office is about to retire from his job. He is a very reserved person. Doesn't talk to people, doesn't socialise and lives a solitary life. Saajan's wife had died a few years back so he just drinks glasses of alcohol and watches a show on TV but there is not even a single glimmer of happiness in him. While Ila, a hindu, a young housewife, totally different from Saajan is going through a bland relationship with her husband, Rajeev who doesn't really converse with her when he returns home after work. So, Ila tries to seek his attention and romance him by sending him very special and tasty food to spice up their relationship. She sends him a lunchbox everyday through the intricate system of traditional food delivery in Mumbai which is taken care by the "Dabbawalas". Dabbawalas are people who send home cooked food to the people who work in offices so that their spouses don't have to worry about travelling and handing the lunchboxes on their own, to their spouses. And mind you, these dabbawalas virtually never mess up, by giving a lunchbox to the wrong person. It always goes to the right person. Ila used to send food to her husband but one day, Ila's lunchbox made for Rajeev mistakenly went to Saajan's desk. Saajan is visibly surprised because he has no one to give him food like this as he eats his food from the office canteen or from outside. Ila eventually realises her mistake through her husband who when he returned said that he ate something else only and through the dabbawala who said the address to which it went and she knew that that wasn't the right address, also scolding him a bit. Ila thinks what to do. The very next day, she tells her neighbour who is an elderly lady about the incident. After taking advice from her neighbour, Ila sends a letter to Saajan, talking about the mix up along with the lunchbox which contains food. (her husband's favourite meal, might I add.) She also tells her dabbawala to send the lunchbox to the same address like yesterday. Saajan again receives the same box and reads the letter and tries to only taste the food but it's so good that he ends up eating all of it. He writes back to her saying that the food was simply delicious and Ila loves it and this kicks off their innocent conversations through paper, through letters and in those letters, talking about each other lives. - While at work, Saajan is introduced to Shaikh a muslim who is new to the office and is set to replace Saajan as the accountant. Saajan is tasked to train him before he leaves the job completely. Shaikh's incompetence initially annoys Saajan who tries to distance himself from him and also tells lies in conversations when Sheikh asks questions about his daily life. But Saajan and Shaikh gradually strike a close bond and friendship with each other. One time, Saajan covered up Shaikh's mistakes at the office thus saving him and his job and becoming the right man for him at his wedding with Mehrunissa as Shaikh never had any parents, he was an orphan. At Ila's home, Ila finds out that Rajeev is having an affair with another woman and is cheating on her. She doesn't fume or anger up but she loses hope towards her marriage with Rajeev. In her next lunchbox letter to Saajan, she suggests moving to Bhutan where there is way lower cost of living than in India. In the very next one, Ila offers Saajan to meet her in person at a popular, local restaurant somewhere in the city before she leaves for Bhutan. Saajan agrees but he is not able to reach the place at the right time while Ila waited, waited and waited but a little later, was compelled to leave the restaurant. The following day, Saajan receives an empty lunchbox which makes him write back to Ila and in that vey letter, he apologises to a dejected Ila but says that he did turn up and saw her from a distance. Saajan said that he just couldn't gain the courage to approach her, who was sitting at the table. He expresses that she looked young and very beautiful but tells her that he is too old for her and advises her to carry on with her life. A few days later, Ila's father, battling lung cancer, died with her mother, grieving over his passing. But after her mother actually confessed to Ila, how unhappy her marriage was with her father. Ila starts searching for Saajan but learns from Shaikh that he has already retired and is headed to Nashik. Ila writes a farewell message to Saajan, stating that she has decided to leave her husband and would move to Bhutan with her young daughter. When Saajan sees this, he changes his mind while en route to Nashik and returns to Mumbai and goes in search of Ila. Ila is last seen waiting for her daughter to return home from school as Saajan gets help from the same dabbawala who regularly picked and delivered that very. - Lunchbox."