Boku Dake no Mono ~Kuruoshii Hodo Kimi ga Suki~

The protagonist is from a prominent family in Japan, and from when he was a kid he lived in a spacious mansion and the adults around them treated him like a treasure.But he hated the world.
But when he met a girl called Hinako he changed, she accepted him like one person.
She don't negate him.Just sended him a shining smile.
She was the only happiness of the protagonist.
But he noticed.Hinako will change.This world,she's parents,she's surroundings, Hinako will be like the other filthy humans.
Thus, when he knew that his father treated the women like his own things, the protagonist couldn't stop.
He get the determination to get Hinako, and called her to the mansion.