Hum Dono is a story that revolves around the lives of four people, Rahul and Anjali, and Vikram/Ajay and Piyasha/Amita.
Rahul ('R Madhavan') and Anjali (Trupti Todarmal) are strangers but have won a world tour together. During their tour in Australia, Singapore and London, they get to know each other. Rahul is a jovial guy while Anjali is reserved. As the tour progresses, they spend time together and Rahul falls for Anjali, although she is still in denial about her feelings for him.
Piyasha/Amita (Malini Sharma) meets Vikram/Ajay Sood (Vishal Singh) on a world tour where they get to know each other and become friends. As time passes, Piyasha tells Vikram that her real name is Amita and she had eloped from home. She later finds out that Vikram’s real name is Ajay Sood and he had been sent by her father to keep an eye on her. On finding out this, Amita gets furious but Ajay asserts her that he started liking her even before he knew her.
• R. Madhavan:He plays the role of Rahul. In the series, he has been depicted as a jolly and a free-spirited person.R. Madhavan is an actor, director, writer, film producer and TV host. He is known for his versatile skills and remarkable roles in both Hindi and Tamil movies, Inferno (1997), Rehna Hai Tere Dil Mein (2001), Anbe Sivam (2003), Rang De Basanti (2006), Evano Oruvam (2007), 3 idiots (2009), Vettai (2012) and Jodi Breakers (2012), to name a few.
• Trupti Todarmal: This actress had a short stint in the film and television industry. She appeared in The Water in Slow Motion (1995).
• Vishal Singh:He played the role of Vikram/Ajay Sood.Vishal Singh is well known for his work in Hindi television such as Dekh Bhai dekh, Kasamh Se, Parvarish, Kuch is Tara, Saath Nibhana Saathiya and so on.
• Malini Sharma: She played the role of Piyasha/Amita.Malini Sharma is a model and actress known for her appearance in the movie Raaz for which she won the Zee Cine Award for Best Female Debut.