ABCD is the story of Raj and Nina, first generation Asian Indian immigrant children who have grown up in America, and their mother, Anju, who is desperately trying in her old age to reconcile her long ago decision to come to America. ABCD revolves around characters who are culturally lost, since they can no longer fully adhere to the customs of the country they have left behind, yet they know they cannot belong to mainstream American culture.
Nina, bright and beautiful, strong headed and promiscuous, uses sex as a shield to avoid intimacy. She is still rebelling against the conservative Hindu values of her mother. Nina detests the Indian custom of arranged marriages so she exclusively dates American white men believing that all Indian men have nothing to offer her. Her attitude changes when her mother arranges a meeting with Ashok, a childhood friend from India who has recently immigrated to the US. He offers her the emotional intimacy she has never felt before, yet she is uneasy about the relationship. Her life is complicated when an old flame, Sam, reenters her life. Though Sam and Nina are not an ideal match, he offers her a social position in life; a rich white husband who makes Nina feel more comfortable in the culture, makes her feel more American. Each man, representing the two cultures, pulls at Nina, trapping her in a tug of war.
Nina's brother Raj is her polar opposite. He is quietly intelligent and emotionally very distant. He long ago agreed to an arranged marriage to Tejal, a sweet and trusting Indian woman who has been in this country for only a few years. Raj is a successful mid-level accountant, vying for a promotion. When he is passed over, it is for a less gifted accountant, his best friend Brian. Raj knows he is a better accountant, a harder worker and more deserving of the job. He feels his race may have something to do with it, but he cannot be sure about the motives of his superiors. A new coworker, Julia, catches Raj's eye. She is an ordinary middle class woman who completely connects with Raj. Raj must choose between the two women. He feels deeply affectionate towards Tejal but does not love her. Yet he cannot break up with Tejal because that would destroy her life since no other conservative Indian boy would touch her. Out of that fear, he does not develop a full relationship with Julia even though it is something they both desperately crave.
Anju, who is Raj and Nina's widowed mother is the third piece of this puzzle. Aged and widowed, she desperately clings to her children by controlling their lives at every turn. Her old world ideas and traditional Hindu values clash with the world outside her home and only serve to keep her children at a distance.
Though Raj and Nina genuinely love her, they can only yearn to live their lives without her interference. She constantly confronts Nina about her promiscuity, believing her daughter will ultimately come around and find a suitable Indian boy. She pushes Raj hard for the promotion that he will never get and ignores the overly long engagement of Raj and Tejal, only looking forward to their wedding day sometime in the future.
In the end, fate forces Raj and Nina to make their decisions. And the paths they choose not only change their lives forever, but have startling consequences for all around them.