Aspiring to join the world renowned Kaleido Stage, 16-year-old Sora Naegino travels to the United States on her own to audition for this prestigious performance company. Upon arrival in the States, Sora becomes the victim of theft and she gives pursuit of the street thief. During this ordeal, Sora encounters a man named Kalos, who appears quite impressed with her tight muscles and the acrobatic feats she performed to stop the thief and retrieve her stolen possessions. While Sora thinks that this strange guy looking her over is just some kind of weird pervert, little does she know that Kalos is actually the owner of Kaleido Stage, which she had set out from Japan to join in the first place.

Due to everything that transpired, as well as being questioned by the police, Sora is late for her audition at Kaleido Stage and is not permitted to try out. After being told to go home and try again next year, opportunity soon knocks when a Rabbit Girl is injured and is unable to perform in the upcoming act. Kalos arrives on the scene, and decides to let Sora fill the now vacated role, much to the dismay of the other members of Kaleido Stage. While Sora’s performance was less than perfect, Sora showed enough potential for Kalos to decide to bring her aboard as a member of Kaleido Stage.

Now admitted into Kaleido Stage, Sora tries to settle in to her new home at the dormitory. While doing so, she is greeted by a strange creature that looks like a doll and calls himself “Fool, the Spirit of the Stage”. Fool claims that only one chosen for the stage can see him, and Sora is that lucky chosen person. While an awkward development, Sora also has to contend with the scorn of her fellow performers. Put off by how easily she got into Kaleido Stage, everyone thinks that Sora simply got in on one of Kalos' whims, so Sora must prove herself to everyone if she is to stay onboard.

With no formal training, not even in ballet, Sora takes up Layla Hamilton’s, the star of Kaleido Stage, challenge to flawlessly execute her famous Golden Phoenix routine. If Sora fails to pull it off, she has to leave Kaleido Stage. With everything on the line, Sora trains vigorously day and night to master Layla’s routine. Her hard work and determination earned her the respect and friendship of Anna and Mia, who were previously skeptical of why Sora was allowed to join the troupe. When finally the critical hour came, Sora failed to grab the swing’s bar and couldn’t complete the Golden Phoenix, but her efforts and nearly flawless routine earned everyone’s respect, and she was allowed to remain in Kaleido Stage, thus beginning her journey to become a Kaleido Star.