Between 1984 and 1985, a cryptic entity known as the Monster with 21 Faces terrorized Japanese confectioners, including Ezaki Glico and Morinaga, through a series of bold crimes. Their actions involved kidnappings, extortion attempts, and product tampering threats, causing significant financial damage and public fear. Despite extensive police efforts, the group, which drew its name from a fictional villain and communicated through taunting, theatrical letters, was never apprehended. The case, marked by the police's struggle to identify the perpetrators, remains one of Japan's most famous and enduring unsolved mysteries, leaving behind a legacy of intrigue and unanswered questions.