Female spy Mayu. Codename "Mayu." A member of "Butterfly," a female intelligence unit secretly established by the Special Investigations Headquarters, she works day and night to prevent heinous sex crimes. Outwardly posing as a pure and elegant female college student, she is in reality a highly skilled spy with exceptional infiltration abilities. She has penetrated numerous criminal organizations, bringing them from within to complete collapse. But now, she suddenly becomes entangled in a horrifying incident. The female spy is completely restrained—escape impossible. Can Mayu endure the hellish torture that awaits her?!