| Director | Karthik Subbaraj |
|---|
1968: Mohandoss is a middle-aged liquor-ban activist whose 12-year-old son Gandhi Mahaan is the exact opposite of him and is addicted to gambling. Sathyavan Soosaiyappan is his friend, who gambles against Gnanodhayam. Gandhi is a prodigy at gambling and always helps Sathya win matches. One time, Sathya keeps on losing and confronts Gandhi, who tells him he has no choice but to make him lose because Gnanam kidnapped his dog Joker. Everyone fights over it, and their parents have to interfere. Mohandoss makes Gandhi promise that he will lead the liquor-ban movement and live as a "Mahaan".
1996: Gandhi is a 40-year-old commerce teacher at the local government school. He is married to Nachi and has a son Dada. On his official birthday, Gandhi leaves for a temple to give alms, where he meets a beggar Manickam, who tells him that Gandhi leads a life-like 95% of people with morals or principles, but cannot lead a life like 5% of people, who do not follow morals or principles in life. At night, Gandhi remembers Manickam's words when Nachi tells Gandhi that she and her friends are going on a trip to Tirupati. Gandhi uses this as an opportunity to enjoy his real birthday the next day and goes to a bar, where he meets one of his old students, Rakesh Christopher alias Rocky, who decides to help Gandhi fulfil his dreams.
Gandhi is then taken to Rocky's father Sathya, who owns the bar, where Gandhi plays rummy and wins a lot of money. Sathya recognizes Gandhi as his childhood friend due to the scar. The next morning, Gandhi returns home late, when Nachi deduces that Gandhi has drunk and leaves him, taking Dada with her, since Gandhi broke the rule of never drinking. Gandhi goes to Nachi's house multiple times and begs for a reconciliation, but is ousted. He decides to live with Sathya and Rocky, and they all come up with selling the liquor that Sathya's father Soosaiyappan made and names the brand Sooraa.
1998: Gandhi, Sathya and Rocky are all rich from selling the liquor and plan to start and lead a syndicate where only their drinks can be sold in the bars in Tamil Nadu. One of the members opposes their leadership, resulting in him being tied away and sent away in a cow truck. Later on, the trio visit a bar and try some strong alcohol, which severely intoxicates them. They are then driven to the rival member who tries to kill Rocky in front of Sathya, but Gandhi drunkenly stops him and fights all of them off. This incident causes Sathya to become a devout Christian and paranoid, and he suggests that they stop selling liquor, while Gandhi convinces him otherwise.
2003: Gandhi, Sathya and Rocky have become influential people in society. However, the Tamil Nadu Government announces that only government-approved liquor is allowed to be sold in bars, and with this development, they decide to visit one of the party members, Gnanodhyam, through his supporter Anthony, whom they then deduce that he is the same Gnanam, one of their childhood friends, through his scar, and he agrees to a deal that Sooraa can be sold in bars.
2008: Gandhi has become a billionaire owning several distilleries, and the gang runs a liquor mafia in Tamil Nadu. The CBI is trying to find evidence to arrest them. At Rocky's wedding, Gnanam proposes a deal to Gandhi that he can let them produce the entire stock of liquor in Tamil Nadu by killing off the DC, which they do. Gnanam then meets Sathya and Gandhi and proposes that they sell their liquor under different brands of lower quality, which Sathya does not agree with, stating business ethics, Gandhi admits that they killed off the collector, where Sathya storms off and Gandhi admits he sees Gnanam as less of a friend than Sathya. With all of this, Gnanam decides to cancel the license of Sooraa, but they know that Gnanam had illicitly had a son, who was Anthony, with a woman in his old colony and use this information to blackmail Gnanam into reinstating the license of Sooraa.
2016: Gandhi leaves for a festival to which one of his gang members, Michael, invites him. In the middle of the festival, a stranger arrives and reveals himself to Gandhi as his son Dada. In this timeframe, Dada kills Michael and tells Gandhi that he was appointed on a special mission to eliminate the liquor mafia.
1996–2016: Dada moves to North India with his mother and relatives, where they receive news of Gandhi's success in the liquor business against Mohandoss's wishes, which angers them all. His relatives convince Nachi to remarry, but she withdraws at the last minute, still faithful to Gandhi. Rajavel blamed Gandhi for his death on his deathbed, which motivated Dada to retaliate against Gandhi. He assaulted someone for trying to make him drink and was encouraged to join the IPS for his revenge. He is soon appointed to the Special Task Force, to dismantle the liquor mafia.
Dada ensures Gandhi that he will not kill him, but he will kill everyone else. It is revealed that Gnanam, who became Deputy CM, wanted to appoint the team to retaliate against the entire group. Gandhi visits Gnanam and tells him to stop the operation before it worsens. Meanwhile, Dada kills Anthony. Enraged, Rocky tries to learn who killed Anthony and Michael, and Gandhi is forced to reveal to Rocky that the officer who killed them both was his son and he can do nothing about it.
Rocky tries to convince Dada to not kill them, presenting himself as an older brother, but Dada kills him and incapacitates Gandhi. Gandhi gets up and fights Dada, but is unable to kill him as his father. Gandhi attempts to convince Sathya to target Gnanam instead of Dada, but his efforts fail as their relationship remains undisclosed. He visits Nachi and reconciles with her, but they cannot convince Dada. She moves into Gandhi's house and lives there, where he asks her to leave with Dada. She talked to the Deputy CM, Gnanam, to dismiss Dada, where Gnanam recognized her in the picture at Gandhi's house.