Why did Sister Korekiyo Shinguji kill him?

Add playmates for the dead sister. Zhengong Temple tells the motive of killing, which was originally to add good friends to her dead sister, and died after being punished. The TV cartoon "On the Broken Projectile" is an animation adapted from the PSP game of the same name. Taking the private Hope Peak Academy as the stage, the animation tells the story of high flyers's desperate campus life in various fields who was locked up in this school and began to gamble for life and death.