A mental hospital for learning to slay gods

Have you ever thought that beneath the neon city lurks monsters from ancient mythology?
Have you ever thought that above the moon above men's heads stands the watchman God?
Have you ever thought that in the crowded modern cities, there are extraordinary people who walk the earth in place of gods?
In the society ruled by human beings, there are countless mysteries lurking;
In those forbidden places of life that no one cares about, live the ancient gods.
Seraph Michael, Hades, Poseidon...
And where did the gods of Bactria go?
In this "human" world, the "mystery" needs to be cleared away!