Musume no Shinshitsu

I had sex with my own daughter - in a dream, of course.

Goto, a university lecturer, had a happy family, with a beautiful artist wife, and smart, cute children… However, this happiness was only a shell. Goto suspects his wife's infidelity by day, and he is plagued by nightmares at night, as his sanity is fraying. One day, Goto came home to find his daughter in tears in her room, which had been vandalized. Convinced that it was his wife, Goto is determined to protect his precious daughter…! An immoral family thriller!

(Source: Kodansha, translated)