Sexual Mother’s Conception [OrcSoft] [English]

The main character, Haruta Kirimiya is the only son of a wealthy couple who lived in a tower block since he was young, and is enrolled in a prestigious private school but is currently semi-reclusive.
His father, Yoshio, who is an elite employee of a large company, concludes that his son is being bullied because he is short and obese, and he despises his son, a “loser,” so much that he devotes himself to work, ignoring his family.
On the other hand, his mother Mizuki , who was raised as a naive young lady, dotes on him, but she lacks knowledge about the growth of boys and treats him more like a child than his actual age. He had a cold hatred for his father, and a dark and twisted love for his young, beautiful and attractive mother.