In a mansion filled with mysteries, there are essential rules that mustn't be broken: It's imperative to remain oblivious to any hint of the "Secret Corridor" and its overseer. Upon starting her job at this enigmatic estate, the maid Ashe stumbles upon a secretive figure who has been living isolated in the house's deepest level. Both, ostracized for various reasons, find solace in secret meetings within a concealed chamber...