Thendral Vandhu Ennai Thodum

An unforeseen incident forces a traditional girl to marry a rogue. Despite their differences it is possible that love will blossom.[5]

Abhinaya's (Abhi's) family is introduced and it shown that she has returned from the United States in order to marry her fiancé, Dharshan. Vetri is a village rowdy who works for Poongavanam. Vetri's mother loves him, whilst his father detests him for going down the wrong path when he was an excelling student. Abhi and her family decide to go to the temple to ensure her wedding goes well; Vetri is on his way to the same temple on Poongavanam's order, as his driver has eloped with a minister's daughter and plans to marry her at the same temple. In the temple, a sage encounters her and predicts that Abhi will wed an rogue, whether they had previously given it any credence. Abhi assists the eloping couple in getting married and the pair do, however Vetri arrives and threatens the newly-wed couple, even attempting to take off the thali that the driver's wife has on. Abhi intervenes and slaps Vetri for continuously attempting to take the thaali off them. In the heat of the argument, Vetri takes a thali off the Thirunankata Amma and ties it around Abhi and leaves. Her family are shocked, as well as Vetri's gang.

A livid Surya decides to file a police complaint against Vetri and the police arrest him. Meanwhile, Sankar Narayan forbids Abhi from entering the house unless she takes off the thali. Abhi's family convince her to undergo rituals to get rid of the thali and she complies, but then realises she has faith in the thali as it was given by God. Abhi refuses to take off the thali and leaves her house - to the anger of her father and the rest of the family barring Padma. Abhi gets Vetri out on bail, but Vetri is not grateful and tells her to get rid of the thali and Sankar Narayan disowns her. A different sage also foretells that Vetri will marry a girl and she will bring prosperity into his life.

Abhi forcefully ushers herself into the slums of Kanchipuram and waits for Vetri outside his house, waiting in the rain and resisting Vetri's friends attempts to usher her away. However, the next morning, Senba (Vetri's rival) ogles and harasses Abhi - leading Kamala to bring her into their house.

Vetri initially dismisses Abhi's attempts to help him comprehend the meaning of love, but Abhi discovers the truth about Vetri and the reasons behind his abrupt change, as well as the fact that Radha, a lifelong acquaintance, is secretly in love with him.

Destiny causes several things to happen in the lives of Vetri and Abhi that finally lead to the two of them becoming close. Vetri mentions that he likes Abhi in the scene when they were both separated from each other and forced to marry other people - Vetri marrying Radha and Abhi marrying Shakthi, a childhood friend of hers. They end up cancelling their respective marriages and confess their feelings to each other and accept each other as husband and wife.

However, Kamala forbids the pair from entering the house after bringing shame to her at the wedding, whilst Vetri's other family members agree to let them live with them on the terrace next to their house.

After being separated for years, Abhi and Vetri cross paths again.[6]

After serving six years for taking the blame of Bhavani's murder at the hands of Nandhini, Vetri is released from prison. He meets with Kalai and Nandhini, from whom he finds out that Abhi had left their home following his arrest, and they don't know where she is. He also discovers that Aranganathan had died while he was in prison and Kalai could not get parole for Vetri to perform his last rites. Vetri refuses to return home and goes around Kanchipuram searching for Abhi and finally ends up in her house, where he finds out that Padma also died while he was in prison. Sankaranarayan, who is now retired and is still livid at Vetri for lying in court that he had murdered Bhavani, tells Vetri that he too doesn't know where Abhi is, but adds that she aborted their child before disappearing. On hearing this, Vetri's love for Abhi turns to extreme hatred, and he leaves her house, refusing to continue his search for her. He once again turns into a rowdy, and also acquires bad habits such as smoking and drinking. He eventually succeeds Poongavanam, who is also dead, as Kanchipuram's main rowdy.

Unknown to anyone including her own family, a heartbroken Abhi, following Vetri's arrest, spent the next eight years in both Rajasthan and Andhra Pradesh. During this time, she clears the Civil Services Examination and becomes a collector. It is also revealed that she did not abort her child, and had told her father prior to her disappearance to lie to Vetri that their child was aborted, as she does not want him to meet her and her child again. Abhi's and Vetri's child turns out to be a daughter, whose name is Sudarvizhi "Sudar" and is eight years old. After fighting with a powerful bigwig in Andhra Pradesh, Abhi is given a government transfer back to Kanchipuram. She reluctantly accepts the transfer as she does not want to encounter her old life again, and leaves for Kanchipuram with Sudar and Vijayalakshmi "Viji", who is Sudar's caretaker. It is further revealed that Radha married Parama and is now a councillor who is unable to stand up to Vetri's atrocities, while Parama continues his shady activities without Radha's knowledge.

When a riot occurs at a temple, the temple is shut on Abhi's orders. Vetri rushes to the temple and breaks the seal, opening the temple. It is at this juncture that Vetri and Abhi cross paths again after eight years. Abhi arrests Vetri for disobeying her orders and further arrests Chittapu, Quarter and Pei for extorting money from the people, based on Radha's complaint. They are all released on bail by Kanmani, a lawyer whom Vetri had helped to study law when she was younger. Kanmani accommodates Vetri and his henchmen in her house, much to her father's chagrin, who is unable to tolerate Vetri's drunken antics. It is revealed that Kanmani has a one-sided love for Vetri.

Parama plots to have Vetri killed as revenge for killing Bhavani. When his goons try to finish him off, Sudar warns Vetri and he fends off the rowdies. However, in the process, Sudar gets injured but this incident causes Vetri and Sudar to become close. They spend a lot of time together, without Abhi's knowledge, and form a strong bond, whilst not knowing that they are actually father and daughter. Vetri does not know that Sudar's mother is Abhi and thinks that Viji is her mother. Sudar also reforms Vetri and makes him give up drinking.

Abhi (and Vetri in parallel) bust a drug scam where drug-infused chocolates are being sold to children. In revenge, the drug smuggler, a don named Ponnaiya (who had clashed with both Abhi and Vetri in the past), decides to kill Abhi. After initially failing to do so with Parama's help, he has his men crash a lorry into the car which Abhi and Sudar are travelling. While Abhi escapes with minor injuries, Sudar is grievously injured and in a coma. Vetri rushes to the hospital, where he realises that Sudar is Abhi's daughter, and is extremely happy on knowing that Sudar is his daughter. However, Kanmani, who is also at the hospital, and fearing that Vetri may reconcile with Abhi, fabricates a story claiming that while Sudar is indeed Abhi's daughter, she is not Vetri's daughter and that her father is Dr. Tharun (who was Sudar's doctor while she was in Andhra Pradesh and contrary to Kanmani's claims, is just a friend for Abhi and is not married to her). She also shares Vetri a photoshopped image of Tharun marrying Abhi and further reiterates the lie that Vetri's biological child was aborted. Vetri believes Kanmani and is distraught, but still decides to maintain his friendship with Sudar and vows to protect her. Meanwhile, Sudar makes a successful recovery and returns home. Upon finding out that Ponnaiya was the mastermind behind the lorry crash, Abhi has him arrested with Kanmani's help.

The incident involving Ponnaiya urges Abhi to find added security for Sudar, and assigns Tharun to find a new bodyguard for Sudar. On Viji's recommendation, Tharun selects Vetri as Sudar's bodyguard, but he doesn't know about Vetri's past with Abhi as well as his rowdyism. Abhi hesitates on hiring Vetri as she is scared that Sudar will develop too close a bond with Vetri, but eventually relents and reluctantly hires him, on the condition that he doesn't tell anyone, especially Sudar, about his past and focus on the job at hand. Vetri moves into Abhi's house and proves to be an excellent bodyguard for Sudar, and the bond between them tightens even more. But, Kanmani joins hands with Parama and publishes an article in the newspaper that Vetri had killed Bhavani. This proves to be the final straw for Abhi, who fires Vetri and expels him from her house, despite Sudar and Viji's pleas.

Meanwhile, Vetri plans to get Kanmani married and have her settled in life. However, Kanmani is adamant on marrying only Vetri and sabotages two wedding proposals arranged by him. Kanmani and her father pressure Vetri to marry her. Vetri initially refuses, but under pressure from Kamala to remarry (Kamala too believes Kanmani's lie that Abhi remarried) as well as Sudar (who asks Vetri to marry Kanmani so he won't feel lonely), he reluctantly agrees to marry her. Viji and Nandhini are shocked on hearing the news, and try to convince Abhi to cancel the wedding and reconcile with Vetri, but she refuses. But Abhi also, at the same time, does not give her thali (which she never removed despite being separated from Vetri) to Nandhini, who has been assigned by Kamala to get the thali since as per an astrologer, it would be inauspicious if Vetri ties a new thali on Kanmani's neck. Later, the saint who had earlier predicted that Abhi would marry Vetri several years ago, appears in front of her and tells her to stop Vetri's and Kanmani's wedding; if not, God will. Abhi is disturbed on hearing this and confides with Tharun about her past with Vetri and why she cannot forgive him and return to him. She bars anyone, including Sudar and Viji, from attending the wedding, but Viji, who has found about Kanmani's evil plan to keep Abhi and Vetri apart, disobeys Abhi and leaves for the wedding with the intention of stopping it and exposing Kanmani.

Viji encounters Chithra in the wedding hall and manages to convince her of Kanmani's evil intentions. But when Chithra confronts Kanmani on the same, Kanmani knocks her out and convinces Kamala and the rest of the family that Viji has come to stop the wedding. Kamala orders Viji to leave. However, Viji manages to convince Chittapu about Kanmani's lies regarding Abhi. At the same time, Vetri (who has become suspicious about Kanmani's behaviour) hires a hacker to trace the mysterious calls that Kanmani had made earlier to further create a wedge in Abhi's and Vetri's relationship and spoil her marriage proposals. The hacker traces the calls to Kanmani. This, along with Chittapu informing him about Kanmani's lies, causes Vetri to get furious and he confronts Kanmani. But Kanmani, who anticipated that these events would occur, lies again, putting the blame on her father for everything that occurred. The wedding is called off, but Sudar's identity is still unknown.

The incidents at the wedding hall slowly instigate Vetri to find out whether Sudar is his child. When he tries to get information from Viji and Sudar on who is Sudar's mother, Viji refuses to tell him, as she wants him to get the information from Abhi herself, while Sudar, per Abhi's orders, lies that Viji is her mother. Meanwhile, Abhi is assigned control of Chengalpattu district as well, and is overseeing a dispute of fishermen and their land being auctioned off in Chengalpattu. Whilst Vetri acts in support of the fishermen, a notorious rowdy, Vellai Raja, threatens Abhi to give him the land, which she refuses to do. Eventually nobody comes to the auction as Vellai Raja threatens everyone who is interested in buying the land. Abhi proceeds to have him arrested. But Vellai Raja escapes just a few hours later and has his men kidnap Abhi from her house in front of everyone in revenge. Vetri hears the news from Sudar and rushes to the sea, where Vellai Raja is planning to dump Abhi into the sea and kill her. Vetri saves Abhi, but both of them are now stranded at sea. With no contact with anyone, they spend a few days at sea, where it is shown that both of them have mixed feelings for each other and also realise some truths, with Vetri in particular beginning to regret taking the blame for Bhavani's death and abandoning Abhi (but Abhi doesn't know that Vetri takes the blame of Bhavani's murder for Nandhini). They soon make it to a remote island, where Vetri asks Abhi about Sudar's parentage. Abhi refuses to divulge any information on Sudar and reiterates the lie that she had aborted their child years ago. They are eventually saved by some fishermen and return home, however Vetri is now confident that Sudar is his daughter, despite Abhi's claims.

Kanmani schemes to stop Vetri from learning that Sudar is his daughter and also to rekindle Vetri's hatred against Abhi, which is slowly disappearing due to the events at sea. She frames Vetri for selling illegal liquor (which is actually sold by Parama and caused the death of six people), despite Vetri actually finding and destroying the entire stock of liquor in front of Abhi, Kanchipuram SP Kabilan and the people. Vetri, now a wanted criminal, escapes to Rajasthan, where Sudar is rumoured to be born, with Abhi and Kabilan in pursuit. He eventually manages to close in on Sudar's birth certificate, but before he can read it, he is arrested by Kabilan, who also knocks him out when he tries to escape. Abhi takes the birth certificate so that Vetri never sees it. While returning to Kanchipuram, Parama's goons confront Abhi and Kabilan, knock out Kabilan and kidnap Abhi. Vetri, who has regained consciousness, fights the goons and manages to rescue Kabilan as well as Abhi. Following the fight, he manages to finally read the birth certificate, which had fallen out of Abhi's bag while she was kidnapped. The certificate reveals that he is indeed Sudar's father. Vetri breaks down in happiness on finding out the truth, and regrets deserting her and Abhi. Kabilan and Abhi realise that Vetri is innocent, and free him. The trio return to Kanchipuram.

Abhi tells Sudar that their father had abandoned them several years ago (she does not know the reason why he abandoned them), so that she stops asking about her father, which causes Sudar to develop a hatred for her father, though she still does not know Vetri is her father. She further blocks all sorts of communication to her home so that Vetri cannot contact Sudar, fearing that he may have found out Sudar is his daughter. Nevertheless, Vetri manages to "kidnap" Sudar and takes her to Kodaikanal for a holiday, where they enjoy and spend their time happily. Vetri informs to Viji that Sudar is my daughter and stays with me. viji gets shocked to hear this from vetri that he found the truth in Rajasthan. Abhi and Kabilan believe that Vetri kidnapped Sudar, since both of them are missing, and being a search for them, with Kabilan even deciding to kill Vetri in an encounter if he is found with Sudar. On Viji's (who is aware that both Vetri and Sudar are in Kodaikanal) advice, Vetri returns Sudar to her home, claiming that he had "rescued" Sudar from a kidnapping gang. Kabilan does not believe Vetri, but on Abhi's request, he does not proceed with the investigation.

Meanwhile, Madhu, who is Bhavani's widow, arrives in Kanchipuram seeking vengeance on Vetri for killing her husband. Kanmani learns of this and (as part of her plan to have Vetri for herself) convinces her to get rid of everyone close to Vetri, including Abhi, instead of killing him outright, then target Vetri once he is isolated. With this in mind, she and Madhu orchestrate the kidnapping of several girls with the intention of causing a deterioration of law-and-order and forcing Abhi's transfer out of Kanchipuram. At the same time, Parama and his men acquire and sell hardcore drugs to schoolchildren with the same intentions as that of Kanmani and Madhu. These two parallel incidents dent Abhi's image and she faces the public wrath for not being able to control both the kidnappings and the sale of drugs. Vetri, fearing for Abhi's safety, "kidnaps" her as well as Viji and Sudar and keep them safely in a mansion, while investigating the kidnappings. He eventually manages to trace the missing girls, but is asked to leave by Kabilan, who is also at the same place. Kabilan steals the credit from Vetri for rescuing the girls and arrests Parama based on his photo being where the girls had been kept. However, the photo turns out to be that of Bhavani's, which had dropped from Madhu's pocket while she was at the kidnapping location. Kanmani has Parama released on bail and instigates Radha against Abhi, claiming that Abhi had ordered Parama's arrest out of vengeance.

• Pavithra Janani as IAS Abhinaya "Abhi" Vetriselvan – Kanchipuram's district collector; Sankar Narayan and Padma's elder daughter; Deepthi's sister; Surya's cousin; Vetri's wife; Sudar's mother
• Vinoth Babu as Vetriselvan "Vetri" Aranganathan – A rowdy and ex-convict who took the blame for Bhavani's murder; Araganathan and Kamala's youngest son; Kalai and Anbu's brother; Abhi's husband; Sudar's father
• Sudar Sam as Sudarvizhi "Sudar" Vetriselvan – Abhi and Vetri's daughter

• Krithika Laddu as Vijayalakshmi aka Viji – Abhi's sister-figure; Sudar's caretaker
• Shaurya Shashank Ramesh as
  • Bhavani – Parama's twin brother (2021-22) (Dead)
  • Parameswaran aka Parama – Bhavani's twin brother; Radha's husband (2022-2023)
• Tharshika as Radha Parameswaran – Vetri's ex-fiancée; Parama's wife (2021–2023) (Dead)
• Sasindhar Pushpalingam as Tharun – A physician from Hyderabad; Abhi's friend and brother-figure
• Feroz Khan as Kanchipuram SP Kabilan – Abhi's friend and helper
• Maria Juliana as Adv. Kanmani – Vetri's one-sided lover
• Auditor Sridhar as Judge Sankar Narayan – Sivagami's brother; Padma's widower; Abhi and Deepthi's father; Sudar's grandfather
• J.Lalitha as Padma Sankar Narayan – Sankar's wife; Abhi and Deepthi's mother; Sudar's grandmother (Dead)
• Shravnitha Srikanth as Deepthi Sankar Narayan – Sankar Narayan and Padma's younger daughter; Abhi's sister; Surya's cousin (2021–present)
• Anjali Varadharajan as Sivagami – Sankar Narayan's sister; Surya's mother; Abhi and Deepthi's aunt (2021–present)
• Dev Anand Sharma as Surya – Sivagami's son; Abhi and Deepthi's cousin; Varsha's husband
• Bharani Elangovan as Varsha Surya – Chidhambaram and Chandra's daughter; Tharshan's sister; Surya's wife
• Supergood Kannan as Poongavanam – A local politician; Vetri's mentor (Dead)
• Premalatha as Poongavanam's wife
• L. Raja as Aranganathan – Kamala's husband; Kalai, Anbu and Vetri's father; Sudar's grandfather (Dead)
• Priya as Kamala Aranganathan – Aranganathan's widow; Kalai, Anbu and Vetri's mother; Sudar's grandmother
• Sathya Sudha as Kalaiselvan "Kalai" Aranganathan – Aranganathan and Kamala's eldest son; Anbu and Vetri's brother; Nandhini's husband (2021–present)
• Raj Kumar Manoharan as Anbuselvan "Anbu" Aranganathan – Aranganathan and Kamala's second son; Kalai and Vetri's brother; Chitra's husband (2021–present)
• Remyaa Joseph as Nandhini Kalaiselvan – Kalai's wife; Bhavani's murderer (2021–present)
• Syamantha Kiran[7] as Chithra Anbuselvan – Anbu's wife (2021–present)
• Krishna Kishore / Manoj Kumar as Tharshan Chidhambaram – Lawyer turned police officer; Chidhambaram and Chandra's son; Varsha's brother; Abhi's ex-fiancé
• Vasu Vikram as Chidhambaram – Chandra's husband; Tharshan and Varsha's father
• Rekha Suresh as Chandra Chidhambaram – Chidhambaram's wife; Tharshan and Varsha's mother
• Gowthami Vembunathan as Eeswari – Radha's mother
• Kausalya Senthamarai / S. N. Parvathy as Aranganathan's mother; Kalai, Anbu and Vetri's grandmother
• Dhanasekar as Gopalkrishna – Vetri's fellow henchman
• Paranthaman as Quarter – One of Vetri's henchmen
• Krishna Kumar as Pei (Peiathevan) – One of Vetri's henchmen

• VJ Vishal as Shakthi, Vetri's childhood friend, Abhi's cousin (9 June - 6 July 2022)
• Hensha Deepan as Ramya, a criminal who was hired by Vetri's rival, Senba, to coerce him and have him arrested for adultery (14 - 25 December 2021)
• Aranthangi Nisha as Angel

It was announced that the show would be released on 16 August 2021.[8]

Vinoth Babu was cast as the male lead and plays Vetri, marking his second collaboration with Abdul Hafeez, after the two worked on Sundari Neeyum Sundaran Naanum together.[9][10] Pavithra Janani was cast as the female lead and plays Abhi, and marks her fifth serial after playing Malar on Eeramana Rojave.

For the new look second part of the show, Maria Julianna was roped in to play Kanmani, a lawyer with a one-sided love for Vetri, whilst Sudar Sam was brought in to play Sudar, Abhi and Vetri's child.[11][12][13]