Cordyceps - Summer of devouring my best friend's sisters

The masterpiece of the sisterly NTR, based on the original work by Shoot the Moon, is finally being made into a live-action version! Mariko, who lost her parents in an accident, protects her younger sister, her two brother Mitsuru, who is being bullied in her class. At that time, Mitsuru's classmate Takashi was the one who helped me. Mariko begs Takashi to help her younger brother until she recovers, and receives a sexy request as a condition of exchange. The demand gradually escalates, and eventually he is taken with an obscene photo, and is threatened and raped by using it as a joke...