For the teenage student Kei—and at least forty‑six others—eternity arrives as the most dreadful twist imaginable ever. Unfortunately, this accomplishment does not transform him into a hero for. To the public and authorities alike, he is viewed as a singular anomaly destined for capture and scientific scrutiny—a half‑human being who must endure countless deaths to advance human progress in the relentless pursuit of knowledge and power, as a living laboratory today.