Majutsu Koutou Gakkou Yuutosei Arisa: Saiai no Ane ga Netorareru Hi

Arisa is a top student at a prestigious magic high school, admired for her skills and beauty. She lives with her beloved older sister, who has always supported her. Their bond is strong, but a dark shadow looms over their peaceful life.

Arisa's sister becomes the target of a sinister plot involving manipulation and betrayal. Using magic and deceit, an unknown assailant sets out to corrupt and take her away from Arisa. The story follows Arisa's struggle to protect what she holds most dear as her world begins to crumble.