My Sister Is a Bit of a Middle Schooler

The end of the Apocalypse virus war allowed Izumi Muneaki, who woke up three years later, to return to his daily high school life. When he was welcoming his younger sister from the countryside after school one day, a beautiful girl fell from the sky and claimed to be his parasite. "King... Please accept it." "This is born of the human heart and sin, the throne of sin." .................................................... "I don't want to be silent and lonely, nor do I want to be numb and escape. If I want to watch the world being baptized by sin, I would rather use my own pain to construct my own path of sin, and use Sakura and I's Throne of Sin to untie the shackles of the apocalypse in this world!" "It's useless! It's useless! Under God's will! Everything is a loss of happiness!" "My King Izumi! Welcome in!" "This world constructed of sin and nothingness melts loneliness!" "God's Paradise Lost!"