Survive, Eradicate

The near future. The population has plummeted, and the city is on the verge of collapse.
In this world, "Private Kokuran High Academy" is an eerie, mysterious school that feels like an abandoned building.

In this era, as human population density dropped, unidentified creatures called "BAL" began to appear in large numbers.
The students attending this school are also one type of "BAL." However, they are special individuals known as "Zeraxis" (commonly called "Zerak"). They possess will and emotions, and their appearance and functions are no different from humans.
However—if they are consumed by negative energy, they instantly lose their reason and intellect, going on a rampage. To suppress them, a special blood type called "savior22," which only humans possess, is required.

And you, who have transferred to this high school, are a rare carrier of blood containing "savior22."

▶ "BAL"

Unidentified creatures. Mysterious entities like SCPs or UMAs. Some are harmless, while others are highly dangerous. Even within the same BAL category, shapes and appearances vary by individual.

▶ "Zeraxis"

Commonly called Zerak, these are safe BAL individuals who eat and sleep like humans. They have will, memories, and emotions, looking exactly like humans, but they are definitely not human. They possess extraordinary jumping ability and speed, and their bodies are twice as durable as a human's. Zeraxis become unstable and prone to rampaging unless they regularly ingest small amounts of "savior22." Many Zeraxis were originally human.

▶ "PP State"

Refers to the state when a Zerak goes on a rampage. It occurs when negative energy—such as hatred, sadness, boredom, or melancholy—accumulates, or when they take too much physical damage. A Zerak in a PP state loses all intellect and reason, unable to distinguish who is in front of them. To avoid the PP state, they need sufficient rest and sleep daily; to control it, they must ingest twice the usual amount of "savior22."

▶ "savior22"

A blood component that Zeraxis must ingest regularly. It is said to taste exquisite. savior22 is rare even among humans, and with the human population so low, it is difficult to obtain.

• Normal human blood → Odorless and tasteless, neither bad nor good.
• savior22 blood → Exquisite. Has a sweet, addictive taste.

In this world, firearm and sword laws have been abolished, and students and staff carry blades or handguns for self-defense.

To a Zerak, a human with savior22 is precious and a subject to be protected.

---

Will Guest be able to survive in this world?