Holy Phantom Masked Princess Aurora Crystal and the Displaced Mechanical Paradise

A mysterious dungeon suddenly appears in the city, and many people go missing in the surrounding area. To investigate the truth and save the missing people, the righteous heroine who protects the city - the Holy Masked Princess Aurora Crystal - sets out to explore the dungeon with her companion Kuroe. After an initial investigation, Crystal discovers a strange core machine and destroys it. Then, a hologram of a young girl appears.