Oneirosea

Oneirosea is a shōnen demographic anime series, with elements from the action, fantasy, and cyberpunk genres. Never heard of it? Well it's pretty obscure.

Oneirosea is set in an alternate universe version of near-future Earth. In this universe, human souls drift out to a dimension called oneirosea when they are dreaming. Inhabitants of oneirosea, called demons, attempt to infiltrate reality by possessing the bodies of sleeping humans. Humans have known about oneirosea for millennia, so they have developed many countermeasures against demonic possession; most notably, Alcyon Corporation is a global megacorporation dedicated to slaying demons, ostensibly to help keep humanity safe. These characters are all employees or former employees of Alcyon.