A young girl named Maya Kitajima works as a waitress in a crowded Chinese restaurant alongside her bitter mother, who constantly tells her she is useless. Despite her difficult life, Maya possesses a hidden, all-consuming passion for acting and an uncanny ability to mimic characters and emotions she observes, a talent she calls the thousand masks. Her life changes forever when she is discovered by Chigusa Tsukikage, a legendary but reclusive former actress whose face was horribly scarred in an onstage accident. Now the head of a small acting troupe, Tsukikage sees in Maya a raw and prodigious gift, the potential to become the next performer of The Crimson Goddess, a legendary and mysterious play whose performance rights belong exclusively to Tsukikage.

Tsukikage takes Maya under her wing, rescuing her from her home life and enrolling her in a brutal training regimen designed to strip away artifice and reveal true emotion. Maya soon finds herself thrust into a fierce rivalry with Ayumi Himekawa, the beautiful and wealthy daughter of famous acting parents. While Maya is a storm of raw, emotional power who literally becomes her characters, Ayumi is a technical prodigy who has fought her entire life to be recognized for her own skill rather than her family name. Both girls share the same singular ambition to prove themselves worthy of playing the Crimson Goddess, a role that demands an actress sacrifice everything for her art.

The story follows Maya and Ayumi as they age and mature, tackling a gauntlet of demanding stage roles that test the limits of their talent and endurance. From classic plays like Little Women and The Prince and the Pauper to original dramatic works, each performance is a battle that pushes them both to evolve. Their competitive relationship is complex, filled with mutual respect, jealousy, and a deep understanding of each other's devotion to the stage. While Ayumi is often considered the genius, Maya is known as the Stage Mania or the Girl of a Thousand Masks for her ability to overshadow every other actor, even in a minor role.

A parallel plot involves Masumi Hayami, the cold and calculating young president of a major entertainment conglomerate, Daito Productions. Masumi is determined to acquire the rights to The Crimson Goddess by any means necessary, which puts him in direct opposition to Tsukikage. However, he is secretly Maya's most devoted fan, sending her bouquets of purple roses and providing anonymous financial support under the name The Purple Rose Person. Maya despises Masumi for his ruthless business tactics, unaware that her mysterious benefactor is the very man she claims to hate. As the series progresses, Masumi finds himself falling in love with Maya, creating a tangled web of hidden identities and unspoken feelings.

The primary narrative arc culminates in the final contest for the role of the Crimson Goddess. After years of grueling competitions, including a pivotal national theater contest, both Maya and Ayumi are acknowledged as the two final candidates. The test to determine who will inherit the role is to perform a difficult one-act play titled The Two Princesses. The 2005 anime series concludes with Maya delivering a breathtaking, transcendent performance that wins the contest, finally earning her the right to learn the secrets of The Crimson Goddess from Tsukikage, while Ayumi gracefully accepts her defeat, determined to challenge Maya again in the future. The series is set against the backdrop of the Japanese theater world, moving between Tsukikages small, struggling company, the high-tech studios of Daito Productions, and various prestigious theater venues across the country.