There are several legends that talk about Succubus, and what could that be? Well, basically they are demons that feed on men, but not by eating or possessing them, but by seducing them, and most of the time in dreams.

And Chigiri is a Succubus... I mean, an Incubus, that's the male succubus. Generally incubus seduce women, but Chigiri's feminine appearance only seduces men.

Now Chigiri has entered your dreams, doing everything to seduce you, to satisfy your hunger, and then leave.