Akaash is working as a tour guide in Bombay. He introduces the tourists to the city he loves (Salaa'm Bombay). When the tour is over, he returns to the slum where he makes his home, along with his grandmother, Shanti, and best friend Sweetie, a eunuch. He donates part of his earnings to the communal collection, with which the group is trying to purchase the land they live on. Contractors show up to tell them the land has been bought, and they would need to raise millions to buy it themselves. Akaash promises he will provide the money as soon as he becomes a famous movie star (Bollywood).

A lawyer, Vikram, arrives in the slum. He has heard about their plight, and comes to offer his services. Shanti invites him into her home, along with his fianc�e, Priya. Vikram explains that he will work for free for them - Sweetie and Akaash are skeptical, but eventually agree. When Akaash discovers that Priya is involved in the movie industry, he tries to get her to cast him, but she explains that she hasn't actually made any movies yet. The only thing she's directing is the Miss India pageant. Sweetie comes up with a plan to sneak Akaash into the pageant and get him some exposure (Love's Never Easy).

Vikram and Priya's father, Madan, are on hand to support her at the Miss India telecast. Madan also wants her to fix the contest so he can win a bet, ensuring he'll have enough money to hire Rani, the leading Bollywood actress, in his new film. Rani and the contestants perform for the audience (Lovely, Lovely Ladies). Just as the winner is announced, feminist protestors crash the pageant, including Akaash. He grabs a microphone, and leads the contestants and Rani (whom he has idolized) in the lively Bhangra. He and the other protestors are thrown in jail for their efforts, but Rani convinces the policemen to free him, and tells Madan that she will only do his movie if Akaash stars opposite her. All his dreams are coming true.

On the set of the film "Diamond in the Rough", Akaash is having some trouble. The crew attempts to film Shakalaka Baby, but once again, Akaash has trouble staying in character. Priya talks to him privately, and tries to encourage him to think more about the character and less about being on camera. He begins to make some headway (I Could Live Here). Sending him off to re-join the shoot, Priya wonders at the emotions that Akaash brings out in her (Is This Love?).

The film is finished, and it's time for the premiere. Shanti arrives at Akaash's apartment, but Rani turns her away. It is vital that nobody knows of Akaash's true origins. The high society guests arrive for the pre-show party, and warn Akaash of the pitfalls of being Famous. At the premiere, Sweetie, Shanti and others from the slum turn up to cheer Akaash on. The movie is a huge success, but when Sweetie tries to approach Akaash, he pretends not to know her. Shanti and Sweetie are devestated, and Priya tries to comfort them while Akaash and Rani move on to another party (Love's Never Easy (Reprise)).

At the Indian Film Awards, the cast of "Diamond in the Rough" perform a song from their film, Chaiyya Chaiyya. Akaash wins the award for Best Actor, while Rani is beaten by another actress. At Akaash's new mansion, the film cast and crew continue to celebrate their success. Priya confronts Akaash about his treatment of his family and friends, and he tries to explain to her why he can't go back. They both acknowledge their feelings for each other (How Many Stars?), before Rani and Vikram find them together. Vikram warns Akaash in no uncertain terms to stay away from Priya.

However, Priya has cast Akaash in her new film, "Bombay Dreams". Rani insists on playing the lead, but won't conform to Priya's idea of a heroine. She quits the movie, dumping Akaash at the same time. Sweetie arrives to ask for Akaash's help. The final appeal to save the slum land is to happen in court the next day, and they need Akaash to support them. His fame and influence would save them. But he is still unwilling to give up the life he's found, and rebuffs her. Priya and Sweetie both wonder why they love a man who could behave in such a way (Hero).

At the slum, Sweetie brings the news that their appeal has failed, and the land is lost. Shanti urges them all to forget it for the moment, and celebrate the feast of Ganesh. Once most of them have gone, the contractors turn up to gloat over their victory, and tell Sweetie that they will begin demolishing the area tonight. It is not nearly enough time for the inhabitants to move out, and Sweetie implores them to speak to their lawyer, Vikram. The contractors laugh - why would they talk to Vikram when he is the one ordering the demolition? Sweetie realizes they have been betrayed, and runs to tell Akaash and Priya (Ganesh Procession).

Sweetie sends Munna to tell Akaash, and confronts Vikram. He admits his deceit, and tells Sweetie that no one will believe her. When she says Akaash will believe her, Vikram tells her that Akaash will not come to her aid any more than he has before. But this time Akaash is coming, and Sweetie warns Vikram that she will tell Priya the truth before their marriage that evening. That is too much for Vikram, and he shoots Sweetie. Akaash arrives just in time to see his friend die. He realizes that he cannot continue with the lie he's been living (The Journey Home).

Akaash arrives just as the bulldozers are moving in. His famous face stops the contractors, who leave for the evening. The group rejoices at Akaash's homecoming, while also mourning for Sweetie. But Akaash is not finished yet - he must tell Priya the truth about Vikram before it's too late. Crashing the wedding, Akaash tells Priya everything. Vikram tries to kill him as well, but Priya comes to his aid. Vikram is taken away, and rather than waste a perfectly good wedding, Akaash and Priya are married, but not before they share the perfect kiss (Wedding Qawali).