Since they were young children, Maki Takano, Ryo Arayama, Mei Sonokura, and Natsume Muroki have been confined within a school for talented students. The institution demands strict adherence to a "no leaving" policy and boasts a rigorous teaching program. Despite the stringent regulations, the quartet enjoys comfortable lives and clings to the hope of a prosperous future upon graduation. All of that changes when a new student, Kiriko Hinatsu, arrives.
Maki is convinced that he knows Kiriko but his friends and everyone else is adamant that they have never met her. Doubting his own memory, Maki approaches Kiriko, who confesses that she had once been a student whose escape was successful. She discloses that the school is merely an experimental facility where students are subjected to drugs that manipulate their memories.
Maki is now aware of the truth and Kiriko requests his aid in breaking out once more and joining her. The offer is tempting, as he will finally be able to experience the world from which he has been isolated for so long. However, leaving means relinquishing the security and opportunities that he has been guaranteed. Maki must make a choice, whether to seek freedom in an unpredictable world or to settle for a restricted but safe life for himself and his companions.
