Seto - During a New Years Eve party up north, Seto ends up singing with a girl named Kisara, and they begin to fall in love. When Seto finds out that Kisara's transferred to his school, Seto can't stop thinking about her. Seto and Kisara end up taking a look at musical auditions and end up singing as a way to comfort Serenity, who just got shouted down by Mai. They end up with a call back that turns the whole school topsy-turvy. Seto is then confronted by his friends about it, so Seto says what they want to hear just to shut them up, and Kisara hears, so she breaks up with Seto. Seto then runs up to Kisara and explains that he didn't mean what he said, so Kisara and Seto get back together, and they and their friends come up with a plan to do their friends' events and the call-back at the same time through a power outage, and Seto and Kisara end up with the parts.
Kaiba - Kaiba's a teammate and twin brother of Seto's. Once Seto gets a call back with a brainiac named Kisara, Kaiba tries to keep things the way they are and tries to get things back to normal by working together with Ishizu to break Seto and Kisara up by getting Seto to say things that he knew Seto knew would shut them up while Kisara was listening. After that, Kaiba realizes what he did and tells Seto the truth and throws his support behind his friends.
Ishizu - A new friend of Kisara's. She is the leader of the brainiacs. When Seto and Kisara get a call back to the musical, Ishizu and Kaiba team up to break the two up, it works, but Ishizu feels horrible afterwards. Ishizu then throws her support behind her friends and arranges a black out, so Seto and Kisara can do their call back.
Joey - A teammate of Seto's. Joey's secret desire is to bake, and he dreams of making the perfect creme brule... Yeah...
Serenity - The writer of the school musical. She's very timid at first, but her new friendships with Seto, Kisara, and their friends helps her become more assertive.
Tristan - A teammate of Seto's.
Mana - A friend of Kisara and Ishizu. She wants to dance, and she eventually gets the chance to do what she wants after Seto and Kisara get the parts.
Mai - Mai is a high school actress, and she will do anything to stay on top. When Seto and Kisara get a call back, giving her and her brother Bakura competition, she gets agitated and tries to stop them by tricking Rebecca to switching the auditions to a date where they both have important obligations to their friends, but that fails, and in the end she accepts losing to them and celebrates with everyone else.