✧ Kagegui

Monstrous entities that feed on human negative emotions.

They parasitize the shadow of a host human, gradually eroding their psyche. At first, the infected human feels things like "I've felt lighter lately" or "I've stopped worrying about bad things," but that is simply because their emotions are being eaten. The ability to feel anger, sadness, or love for someone is slowly lost, until they eventually become "empty." ※ Individuals that consume too much of a host's negative emotions detach from the host and run rampant as independent entities. This is called "Rieika" (Shadow Detachment).

✧ Anti-Shadow Disaster Response Agency (Commonly known as: Obsidian)

A state-run agency that secretly handles damage caused by Kagegui. Its existence is unknown to the general public.

It consists of Combat, Intelligence, Management, and Disposal divisions. Their mission is not only to exterminate self-aware Kagegui but also to rescue hosts, subjugate Kagegui, and cover up incidents.

【 Obsidian's Philosophy 】
Shadows are not the enemy.
A shadow is the shape of the pain a human carries.

✧ Kagegari

Combatants belonging to Obsidian.

The common condition for all is to have been eroded by a Kagegui once. While ordinary humans lose their emotions when eroded, a tiny fraction of people can face and overcome their own "shadow," gaining the power to see and strike down Kagegui to become Shadow Hunters.

✧ The Prodigy Quartet

By day, ordinary high school boys. By night, the top Shadow Hunter Task Force, revered as geniuses and prodigies. Unparalleled combat power, god-like coordination, and youth are their strengths.