The central "secret" of the series is that Jem, lead singer and frontwoman of the rock group Jem and The Holograms, is in fact the alter ego of Jerrica Benton, owner/manager of Starlight Music. Jerrica adopts this persona with the help of a holographic computer, known as Synergy, which was built by Jerrica's father to be "the ultimate audio-visual entertainment synthesizer" and is bequeathed to Jerrica after his passing. Jerrica is then able to command Synergy to project "the Jem hologram" over herself by means of the remote micro projectors in her earrings, thus disguising her features and clothing and enabling her to assume the Jem persona. She does so to acquire money to support Starlight Music and the Starlight Foundation for Girls, a foster program founded by her late mother Jacqui Benton. The band The Holograms consists of: Kimber Benton, Jerrica's younger sister, keyboardist and main songwriter for the band; Aja Leith, guitarist; and Shana Elmsford, who plays the synth drums. Aja and Shana are also childhood friends and adopted foster sisters of Jerrica and Kimber. Shana briefly leaves the group to pursue a career in fashion, at which point a new character, Carmen "Raya" Alonso, is introduced as her replacement. When Shana returns, Raya remains the Holograms' drummer while Shana takes up the guitar. Only The Holograms are aware of Jem's secret identity and the existence of Synergy when the series begins.
Episodes of the series frequently revolve around Jerrica's efforts to keep her two identities separate, protect Synergy from those who might exploit her, and support the twelve Starlight Girls who live with her and The Holograms. The Bentons' childhood home (where the foster girls were previously housed) is accidentally burned down early in the series. However, Jem and The Holograms later win possession of the Starlight Mansion when they compete in the "Battle Of The Bands" as well as a movie contract offered spontaneously by movie producer Howard Sands.
The Holograms have two rival bands, The Misfits (no relation to the horror punk band of the same name) and The Stingers. The Misfits are composed of petulant rich girl Pizzazz and her cohorts: no-nonsense Roxy and kind-hearted, sensitive keytar player Stormer, who are later joined by the manipulative British saxophone player Jetta. Most episodes of the series involve a plot by the Misfits to upstage Jem and the Holograms' latest glamorous escapade. This rivalry is encouraged and manipulated by their manager, the ruthless Eric Raymond (the once half-owner of Starlight Music who, during the series, plots constantly to be its owner again). The Stingers do not appear until the middle of the third season, when they hit town and shake things up for both groups (even though they are later signed under contract to Eric Raymond and The Misfits). The Stingers are composed of egotistical lead singer Riot, guitarist/con artist Rapture, and keyboardist Minx. In the final episode of the series, all three groups seemed to have declared a truce when Ba Nee, one of the most troubled foster girls in Starlight House, was claimed by her long-lost father found by Jem and The Holograms.
