"In the paradise between life and death, you will know of your sins—"
The protagonist, Blanco, awakens in an abyss of darkness with no memories. Surrounded by darkness, he wanders through the pitch black forest as far as his feet can take him, with no knowledge of who he is and where he came from.

After making it through the despairingly long path of darkness, he comes across a field of pure white flowers spread out in front of him. A girl in white stands there, speaking to him.
"Welcome to the garden of white... Here, all are cleansed of their sins."

In a pure white paradise where sins are forgiven, he gradually remembers his sins...

[Translated from Official Site]