Normally, these two dimensions would never intersect, but having possessed all material substances, the demons are now intruding on the material world.
Each season is available in its Japanese with English subtitles form as well as its English language dub.
With the setup between Aniplex USA and Funimation now, the first first two seasons of the show have now made their way over to HBO Max for streaming.
Plot Concept: “Assiah, the realm of humans, and Gehenna, the realm of demons.