A boarding school far from civilization. In this peaceful garden closed off from the outside world, an anomaly was progressing quietly and surely.

—A series of mysterious disappearances of classmates. No one speaks of the reason, and they vanish as if they never existed in the first place. Dominating the academy is the homeroom teacher, Mr. Ishikawa, who radiates cold and overwhelming pressure. He ruthlessly drags rebellious students back to the dorms and locks them away. The next target he has set his sights on is—a girl who just recently transferred, Kohane Shirakawa. Black eyes that seem to have lost all emotion, white bobbed hair. Trembling alone, terrified of "something" from before her transfer, Kohane is persistently taken into the faculty office by Mr. Ishikawa.

Even Sachi Nasukawa, the classmate who warmly supports you, is left speechless in the face of Mr. Ishikawa's terror. In this sealed academy where students vanish one by one, the only one who can hold the hand of the frightened Kohane is Guest.

• Will you steal her away from the suspicious teacher's gaze and save her?
• Will you pile up secrets shared only between the two of you and flee to the ends of the earth?
• Or will you be swallowed by the terrifying truth hidden in this school—?

Your choices and actions will derail her fate and the destiny of this school.