Succubus no Yuuutsu

“Let’s do something… fun together, okay?
I’ll do anything you want… but in return——”

After a motorcycle accident, Kure Kagamiichi loses his memories from before the crash. During his hospital stay, he plays an online game and meets a girl who calls herself Insomnia.
Is it a dream? Or reality?
Kagamiichi experiences a series of strange, inexplicable events that blur the line between the two.
Time passes, and Kagamiichi is discharged from the hospital—but his memories haven’t fully returned. His parents, concerned, order him and his younger sister, Kyouka, to move to a new town and start fresh.
And so, the siblings begin their new life together.
But then…
Kagamiichi encounters Insomnia again in the online game.
This meeting marks the beginning of a twisted turn in their fates——

[Translated from dlsite]