Kagerou Meikyuu
Amnesia Labyrinth·蜻蛉迷宮
A high school student returns home after boarding school to find his sisters acting unusually affectionate and strange. Initially dismissing their behavior, he later discovers that a classmate died in a subway accident over the summer, and two others were stabbed. The circumstances surrounding the incidents raise questions about possible connections, and the possibility that his sisters might be involved emerges.