Ema Mayumi, the wife of Shirogane Shusaku, the newly elected mayor of TeiCITY, is a woman harboring a dark past she cannot reveal even to her husband. Born into the noble Gishu family, she inherited the bloodline of an ancient masked warrior. In her youth, she fought as the legendary "Beautiful Girl Mask Sanctuary," protecting the city from evil and upholding justice. The mask she wore was not only a symbol of protection but also a sacred artifact meant to preserve her life. Now, after years of silence, she must once again don that mask—but why?
To eradicate corruption and conspiracy spreading across the city, Shusaku enacts a new policy called the "Special Harmful Organization Control Act," targeting the destruction of the rising cult group "Dorgaia Church." However, the church's archbishop, Baros, appears to be a model citizen while secretly maintaining deep ties with the city's elite. Under his command, devoted followers work in the shadows, executing a sinister plot to seize control of the entire metropolis.
One day, Shusaku is involved in a suspicious traffic accident, and Ema Mayumi becomes a victim of a violent attack. As she fights off her assailants, doubts about the true nature of her husband's accident begin to surface—and those suspicions grow stronger each day. Eventually, she resolves to reclaim her masked identity and confront those responsible. But her path leads directly into the heart of the Dorgaia Church's headquarters.
Though she defeats waves of attacking cultists, the scent of incense lit by Baros overwhelms her senses, causing her to lose consciousness. Captured, she is stripped naked, tightly bound with rope, and forcibly unmasked. At that moment, she learns the horrifying truth behind the mask she wore and the secret legacy of the Gishu family. With the divine power within the mask now lost, she is plunged into an abyss of despair… [BAD END]