Mashou no Kao 1

Hayama Keiichi always dreamed about hot sex with his childhood sweetheart, but one day she transformed in his dream into a mysterious beauty with perfect breasts and seductive eyes. The next afternoon, Keiichi came back from school to find that very same woman masturbating in his room!

His mother introduces her as Reika. Since her parents died in a car accident, Reika has been taken in by Keiichi's family. But Keiichi knows there's some dark truth behind this woman, and he has a hunch his prophetic dream wasn't a dream at all.