To you who will eventually become a monster

＿＿＿xx years, a certain disease was prevalent on the Alverden continent. Its name was 'Nocturne Syndrome'. The disease transforms those who contract it into grotesque monsters, eroding even their minds. There is no known cure, nor is the cause understood; it appeared suddenly one day. People were swallowed by a vortex of fear, and began to slaughter the infected. 'Nocturne Syndrome' marks the end of a person as a 'human' from the moment they contract it, and both the infected and their relatives become targets of discrimination. Amidst all this, there are those who fight today to protect their families, to protect their loved ones. How will you live in this cruel world?

■Alverden Continent
The northern continent dominated by mist and cold winds.
Magic has declined, and it is the “Age of Half-Belief,” where religion and sorcery are mixed.
Kingdoms are in disarray, and farmers constantly live in fear of hunger and war. In the past, a magical civilization flourished, but the civilization collapsed due to a great disaster called the Great Collapse (Catastrum). The darkness of that great disaster remains in the world today.

▼Valmrei Kingdom
The most prosperous kingdom on the continent. A gloomy country with forests and ancient castles, where the disease was first confirmed. The infected are thoroughly isolated, and even their relatives are not allowed within the country.

▼Edelheit Holy See
A theocratic state. It proclaims the disease to be a “trial for sin” and detains the infected. Rumors spread that they are carrying out mass executions in the dark, calling it “purification treatment.”

▼Nordun Borderlands
The land of the north, closed off by snow and ice. A region for isolating the infected from the Valmrei Kingdom. A “lawless wilderness” where many former humans who have become monsters roam.

▼Eira's Deep Forest
A giant forest that no one approaches. A giant primeval forest. It is said to be “the land where the source of the disease was born.”

■Nocturne Syndrome
◎Symptoms
・Early Stage
Black vein-like lines appear somewhere on the body, and nightmares and auditory hallucinations are heard at night. Reason is still normal.
・Middle Stage
Physical abilities and healing abilities increase unnaturally, and emotional fluctuations become intense. Some parts become monstrous. The more fear intensifies, the faster the progression.
・Final Stage
Skeletons, muscles, and various parts are distorted, and they are no longer beings that can be called human. They have completely transformed into monsters.
◎Source of infection, treatment
Unknown

■Nocturne Hunters
Those who hunt the beings that have become monsters due to Nocturne Syndrome, the 'Nocturne Beasts'. Many harbor a strong aversion to Nocturne Beasts, and they execute the Nocturne Beasts in cruel ways.