A mysterious entity that Haruto is often followed by in the dream world. She often refers to him per "big brother", much to his confusion. According to Katsumi Kanzaki, tales of her existence have circulated for ages, mostly in relation to the Sleeping Beauty Syndrome, but no man has ever been able to see her, with Haruto being the first one to do so.

Spoiler

In the finale, she's revealed to be a fragment of biblical Eve that split from her original self, having disagreed with her hatred of God and men.