When their Internet router is destroyed the four friends need money to restore their Internet connection. Oliver has a crush on Emil's sister, who loves BoyBands, so he suggests they earn money by participating in the schools Band Battle.
A.J. and Mikkel try to earn money by selling their home-made energy drink during recess. When the school bullies steal from their shop, they decide to sign up for the Band Battle to beat Sten and Marcus once and for all.
Emil is afraid to sing alone, so Oliver offers to sing playback to Emil's voice. When they enter the stage, their song is spoiled by Sten and Marcus. Depressed they go to the basement, where A.J. produces an improved version of their song.
The boys' song has become a major hit on YouTube, but no-one believes that it's Emil, Mikkel, A.J. and Oliver that are behind it. Suddenly, they are contacted by the agent Ricco La Cour, who wants to sign a contract with the boys.
The boys ask Mathilde for advice on how to look like a boy band. She takes them shopping before their meeting with the agent. Oliver tries to tell Mathilde that he likes her, while Mikkel convinces his granddad to appear as their manager.
To convince Ricco La Cour that they are a real boy band, the boys need to book a suite at the hotel. While Oliver and Emil trigger an alarm, A.J. sneaks into the reception and books a room. Only thing left is to convince the receptionist.
Ricco La Cour has arrived at the hotel, where the boys have cheated their way to an exclusive suite. Granddad and unexpected room service, almost spoil their plans, but they manage to convince La Cour that they are real stars.
The boys arrive at the SuperStars HQ in a limousine, where they are about to have a press-release on YouTube. Their class mates follow the live-stream, where their real identities are revealed. By mistake A.J. reveal their location.
Oliver tries to tell Mathilde that he likes her, but his plan is ruined by some intrusive fans. At school BaseBoys is met with cheers. Sten and Marcus yet again tease Emil, but this time he answers back with a song that makes fun of them.
BaseBoys are making their first music video. Emil has trouble with his anti-asthma spray and A.J. discovers that Oliver has a crush on Mathilde. Emil has trouble following the moves and the director removes him from the video.
BaseBoys have to make a new hit and Mathilde has gotten the boys invited to a party with the super star Liam. Mathilde is not on the guest list, so Oliver sneaks her in, only to find that she goes directly to chat with Liam.
Mathilde is going on a date with Liam in the bowling alley. In order to keep an eye on Mathilde Oliver invites Lærke to go bowling. When Liam leaves the date, Oliver tries to comfort Mathilde. Ricco La Cour has a big surprise for the boys.
The boys arrive at Ricco La Cour's studio unprepared for the song he wants them to record. The boys panic and Emil fakes an asthma attack. Back in the basement, Oliver reveals he has a new song and he demands to sing it.
BaseBoys are going to perform live on TV. There's a bad vibe between the friends and Oliver is sad that he's not allowed to be lead singer. Emil gets an asthma attack and has forgotten his inhaler.
In order to get to sing their new song, Oliver has hidden Emil's inhaler. When Emil finds it, the others have already performed. He gets disappointed and angry, which gives their following interview an unexpected turn.
Emil doesn't show up for the video shoot. He is sure someone from the band hid his inhaler. Oliver decides to visit Emil, to try to get him to come, with the thought that he can use the visit to invite Mathilde on a date.
BaseBoys meet their fans for the first time, but don't know how to handle it. Oliver tries to text Mathilde and talk to the fans at the same time. Emil gets curious and wants to know who Oliver is texting.
Mikkel, A.J. and Emil hold an audition to find a new band member. Oliver feels bad for all he has done, when he receives a text from Mathilde. She invites him on a date, but the date doesn't go as expected.
Ricco is furious that BaseBoys haven't fulfilled their contract, so he does all he can to get his lost money back. To prevent granddad being kicked out of his house, Mikkel and Oliver need to get the band back together.
Mikkel and Oliver decide to try to get the band back together. With assistance from Mathilde they manage to convince Emil and A.J. Their friendship is on the edge, but they agree to perform a charity concert to save granddad's house.
It's time for the concert. Mathilde has helped getting all the equipment needed, and the donations are pouring in. Ricco shows up with a megaphone. He tell the fans that BaseBoys are fake and forces Oliver to sing live.
With the concert falling apart and the fans not knowing what's going on, Oliver tell the fans the truth. When Emil starts to sing, the donations start pouring in again. Ricco threatens to call the police and BaseBoys realize they have failed.
