Ashiaraiyashiki no Juunin-tachi.

More than twenty years ago, an evil summoner committed "Great Summon". One third of human beings were killed, and devils and monsters invaded the Earth.

One day, a painter, Tamura Fukutaro, moves into an apartment house called "Ashiaraiyashiki" and gets involved in the troubles of his non-human neighbors.

It's the beginning of a severe battle among gods, devils and the ruler "The Central".