Death Note: Desu nôto2006

Rem:
Light Yagami, Misa has refused my offer to help her escape, no doubt because she knows it would cause you trouble, since the police would then have proof of her powers. When her suffering became more than she could bear, she started begging me to kill her. All of this because she wants you to love her. I could not possibly let it go on like that. I couldn't bring myself to do it. There was only one way to save her from her suffering.

Light Yagami:
Forfeiting ownership of the Death Note.

Rem:
Yes. If Misa forfeits ownership of the Death Note, all her memories related to it would disappear. All the murders she committed with it, the fact that you are Kira, all those memories would be gone. Your secret would be safe. Also, Misa would no longer be able to see Ryuk or me, either.