Roja follows a kind, optimistic girl who was raised in the orphanage of Shanthamoorthy. She happens to meet her biological father, Tiger Manickam, but they remain unaware of their genetic relationship. Roja is looking for a lawyer to represent Shanthamoorthy, who was falsely accused and arrested for Bhaiya Ganesh's murder, which was committed by Sakshi with Priya by her side. The lawyer she finds is Arjun, a leading criminal lawyer who is humble despite his wealth.
Arjun's family had planned his engagement with Priya (masquerading as "Fake Anu"). However, due to traumatic circumstances in his past, such as Sakshi's betrayal and the death of Arjun's friend Venu, Arjun forswore love and marriage. Therefore, he had no intention of marrying Priya. Arjun agrees to accept Roja's case on the condition that she would consent to one-year contract marriage with him. She agrees, and the two go to the temple on Arjun's engagement day. The wedding takes place with the help of Roja's friend Swetha and Arjun's assistant, Naveen. After registering the marriage, Arjun and Roja proceed to the engagement venue, where Arjun announces to his family his marriage to Roja, which stops the engagement. Roja goes to Arjun's house, where the two of them pretend to be husband and wife in front of the family. However, with time, Arjun discovers Roja's good qualities and falls in love with her. After a few struggles, Roja also falls in love with Arjun. Once the contract is terminated, the couple begins their life as a legitimate husband and wife in a supportive relationship.
Priya, who calls herself Anu, claims to be the daughter of Arjun's uncle, Tiger Manickam and his wife Shenbagam. (This same character, Shenbagam, is missing and presumed dead, but she is actually alive, suffering amnesia.) Priya works for a criminal mastermind, Sakshi. After failing to marry Arjun and enjoy his family’s wealth, her primary goal becomes to marry Arjun's brother, Ashwin. She is cunning, and her charm wins over Arjun's grandmothers Annapoorni Manickam, Yasodha, and Balu, who always supports her even though she often humiliates Roja. Although Arjun's parents (Prathap and Kalpana) and Arjun's brother (Ashwin) support Roja, other family members dislike her. Due to unforeseen circumstances, Ashwin and Pooja marry without their families' knowledge, except for Arjun, Roja, and Kalpana.
Priya and Sakshi attempt to discredit Roja. They also go to great lengths to remove her from the house and kill her, but they fail to succeed in these efforts. Eventually, Arjun proves Shanthamoorthy's innocence in court and gets Priya and Sakshi arrested.
Annapoorani and Manickam both fake acts of being brainwashed to convince Roja to release Priya from jail. Annapoorani also arranges a reception for Arjun and Roja. When Priya and her team light a fire in an enclosed space, Arjun and Roja manage to escape; Priya, however, falls from a great height in trying to flee and ends up in a coma. Roja is blamed for this accident and sent to jail, where Sakshi, along with the help of Tiger Manickam, frequently attacks Roja. Arjun and Chandrakantha intercede to save her from these assaults. In an effort to ensure Roja's safety, Arjun kidnaps Priya. After a long battle in the court between Arjun and Tiger Manickam, Arjun blames Annapoorani, and Balu confesses the truth by playing a drama that he killed Priya. When the character Naveen brings Priya to the courtroom alive, Annapoorani is punished with 24 hours of jail time for trying to kill Roja and Arjun. Priya is granted bail on medical terms, and Roja is finally released.
With the help of Sakshi and Divya, Priya brings the Saraswati nurse home to play the role of Shenbagam. At the same time, Roja fights and performs pooja to get her mother back. While performing the final ritual, Shenbagam enters and saves Roja. Eventually, Shenbagam gains her old memories back, and all accept Roja as Arjun's wife. As the first night is arranged, Priya is furious and tries, but fails, to spoil it. The true face of Priya is revealed when she plants a bomb in Shenbagam's Locket. They immediately decide to take a DNA test. Priya raises concerns over Ashwin and Pooja's marriage to stop it. But to her shock, Annapoorani accepts their marriage, and their first night is arranged.
To stop the DNA test, Priya endeavors to kill Roja. While Shenbagam and Roja are driving in a car, Priya stops and shoots Roja. But unknown to her, Arjun has removed the active bullet. Chandrakantha then arrests Priya. To deceive their opponents, Arjun makes arrangements with Ashwin, Pooja, and Naveen to convince others that Roja is dead. He informs each of his family members of the plot except for Yashoda and Balu.
Arjun entices Roja to act possessed to extract the truth from Priya. After being frightened for two days, Priya confesses the truth to Chandrakantha, and Arjun also promises to tell the truth in court. Meanwhile, Neelambari, an old rival of Priya and Roja, has entered the show, digging up the past. Neelambari wants to seek revenge on Priya and Roja. With the help of her brother and Sakshi, they frantically search for Priya and Roja, and they also attack Shanthamurthy. Eventually, after a lot of twists, she is arrested.
After this temporary resolution, Roja informs Arjun that she is pregnant. Then, a previous enemy of Arjun, JS, joins up with Priya to kill Roja. They ultimately fail in this task, but they do push Roja into a river, causing her to lose her memory of Arjun and her family. Next, Chandrakantha introduces Jessi, a Roja look-alike. When Roja finally regains her memory, she attempts, and eventually succeeds, in performing pooja for the well-being of her unborn child. This irritates Priya, Yashoda, and Balu. Meanwhile, Priya learns of her real parents, Jayaseelan and Kamala. Js doesn't believe Priya, so they go to Roja to confirm what happened. The family joyfully embraces Roja as the first heir of the family, leading Pooja to feel abandoned and jealous. The show ends with Pooja teaming up with Arjun's arch enemy JS and Roja's arch enemy Priya to create more trouble for Roja.
Anu, alias Roja / Real "Anu": Shenbagam and Tiger Manickam's elder daughter; Moorthy's adopted daughter; Jessica's twin-sister; Prathap and Kalpana's first daughter in law ; Arjun, Ashwin, Deepa, Koushik, and Malar's cousin; Pooja's co sister and best friend ; Arjun's wife; Velan's mother; Priya, Yasodha and Sakshi's arch enemy (2018-2022)
SI. Jessica: Tiger Manickam and Shenbagam's younger daughter; Victor and Rosy's adopted daughter; Roja's twin-sister; Arjun, Ashwin, Deepa, Koushik, and Malar's cousin; Arjun's sister in law best friend and henchmen (2022)
Sibbu Suryan as Advocate Arjun: A criminal lawyer; Prathap and Kalpana's elder son; Ashwin and Deepa's brother; Roja, Jessica, Koushik, and Malar's cousin; Pooja and Jessica's brother in law ; Roja's husband; Velan's father; Sakshi, JS, Shyam, Priya and Yasodha's arch enemy (2018-2022)
Recurring
Shamili Sukumar / VJ Akshaya as Priya: Fake Anu; A money minded criminal corrupted girl JS and Kamala's daughter; Roja and Arjun's arch enemy; Sakshi and Yasodha's best friend (2018-2021) / (2021-2022)
Gayatri Shastry as Kalpana: Prathap's wife; Arjun, Ashwin, and Deepa's mother; Roja and Pooja's mother in law and Velan's grandmother (2018-2022)
Venkat Renganathan / Shankaresh Kumar as Ashwin: Prathap and Kalpana's younger son; Arjun and Deepa's brother; Pooja's husband; Roja's brother in law (2018-2021) / (2021-2022)
Smriti Kashyap as Pooja: Purushotaman and Prema's daughter; Ashwin's wife; Prathap and Kalpana's second daughter in law ; Roja's co sister and best friend ; Arjun's junior lawyer and sister in law (2018-2022)
Vadivukkarasi as Annapoorani: Vijayakumar's wife; Shenbagam, Prathap and Yashodha's mother; Arjun, Roja, Pooja, Jessica, Ashwin, Deepa, Koushik and Malar's grandmother; Velan's great-grandmother; Purusotaman's arch enemy (2018-2022)
Dev Anand Sharma as Balachandran, aka Balu: Yashodha's husband; Roja and Arjun's enemy and Priya's henchmen (2018-2022)
Ramya Ramakrishna / Kavyavarshini Arun as Yashodha, aka Yaso: Annapoorani and Vijayakumar's younger daughter; Shenbagam and Prathap's sister; Balu's wife; Koushik and Malar's mother; Priya's best friend and henchmen and Roja and Arjun arch enemy (2019-2021) / (2021-2022)
Dr. Sharmila as Shenbagam: Annapoorani and Vijayakumar's elder daughter; Prathap and Yashodha's sister; Manickam's wife; Roja and Jessica's mother; Arjun's mother in law and Velan's grandmother (2018-2022)
Rajesh as Advocate. Tiger Manickam: A criminal lawyer; Shenbagam's husband; Roja and Jessica's father; Arjun's father in law and Velan's grandfather (2018-2022)
Sowmya Rao Nadig / Sunitha Srinivasan as Sakshi: A money-minded criminal corrupted girl; Arjun and Roja's arch enemy; Priya's best friend (2018-2019) / (2019-2022)
Shiva Subramanian as Prathap: Annapoorani and Vijayakumar's son; Shenbagam and Yashodha's brother; Arjun, Ashwin and Deepa's father; Roja and Pooja's father in law and Velan's grandfather (2018-2022)
Rani as AC. Chandrakantha: Arjun's best friend and henchmen
Hussain A. K. as Navaneetha Krishnan: Arjun's best friend henchmen
Latha as Canada Kamakshi: Annaporani's elder sister
Due to the COVID-19 outbreak in India, Roja and all other Indian television series and film productions were suspended from 19 March 2020.[6] Three months later, shooting was permitted, and the team commenced filming in July.[7] The show telecasted new episodes on 27 July 2020.[8] With the increase in COVID-19 cases in Tamil Nadu, the production was once again suspended in mid-May 2021 for a few weeks.[9][10]
Initially aired at 3:00 PM IST, positive audience reception led the station to reschedule the show to a prime time slot of 9:00 PM IST in early 2019. Within three months, the show was shifted once more to 7:00 PM IST. It was shifted again in 2021 to 9:00 PM IST.[6][20][21]