SDMF-049 | My sister will forget by tomorrow that I have sex with her every night.

I have a secret that I can't tell anyone. I keep having sex with my sister, whose memory resets when she sleeps due to the shock of a certain incident. At first, I wanted to somehow help her with shock therapy... But the more I continue, the more my heart feels fulfilled... Yura has become a convenient sister for me... I'm sorry I'm such a brother... I don't understand either...