Gas Mask Girl

A string of murders known as the "Bagmen Incidents" is attributed to a mysterious girl in a sailor uniform who hides her face behind a gas mask, nicknamed "Mask-san." One day, a boy named Watta encounters her by chance. To his surprise, he recognizes her as someone he knows from school. The story explores the unfolding mystery as this enigmatic figure becomes the center of both conflict and everyday school life.