It’s about incest.
Only sort of about incest...
The father adopted a boy from the orphanage rather than let his wife's son from adultery inherit his assets.
At some point, that illegitimate son began sexy assaulting the adopted son. Because the adopted son had never been shown any affection, he developed a twisted dependence on his older brother.
The scenes with the boys in high school were the adopted son, who is the student body president, and the vice president, who was a new character.
It's not about incest. They were step brothers.
excuse me but what the fuck happen in chap 3: brothers continuously. It is not sufficient. I dont understand