The Monster with 21 Faces (かい人21面相, Kaijin Nijūichi Mensō) was a name (originally of the villain in Edogawa Rampo's detective novels) used as an alias by the person or group responsible for the blackmail letters in the Glico Morinaga case in Japan. Variations of the name's translation, including “the Mystery Man with the 21 Faces” and “the Phantom with 21 Faces”, have also been used in articles and books featuring the case.
The Monster with 21 Faces sent its first letter on May 10, 1984, to the giant food company Ezaki Glico following the kidnapping and escape of Katsuhisa Ezaki, president of Glico. The letter stated it had laced the company's confections with potassium cyanide soda, and it later threatened to put them on store shelves. None of these poisoned candies were found, but Glico products were removed from stores, resulting in a loss of more than $21 million and the laying off of 450 part-time workers.
Meanwhile, the Monster with 21 Faces also sent letters to the media, taunting police efforts to capture the culprit(s) behind the scare. An excerpt from one such letter, written in hiragana and with an Osaka dialect, reads, “Dear dumb police officers. Don't tell a lie. All crimes begin with a lie as we say in Japan. Don't you know that?” Another taunting letter was sent to Koshien police station. “Why don't you keep it to yourself? You seem to be at a loss. So why not let us help you? We'll give you a clue. We entered the factory by the front gate. The typewriter we used is PAN-writer. The plastic container used was a piece of street garbage. Monster with 21 faces.”
On June 26, the Monster with 21 Faces issued a message proclaiming its forgiveness of Glico, and subsequent harassment of the company ceased.
After ceasing its harassment of Glico, the Monster with 21 Faces began targeting Morinaga, another confectionery company, and food companies Marudai Ham and House Food Corporation with similar criminal campaigns, using the same alias.
In October 1984, a letter addressed to "Moms of the Nation" and signed by the Monster with 21 Faces was sent to Osaka news agencies with a warning similar to those sent to Glico. It stated that 20 packages of Morinaga candy had been laced with deadly sodium cyanide. After receiving this letter, police searched stores in cities from Tokyo to western Japan and found over a dozen lethal packages of Morinaga Choco Balls and Angel Pie before anyone was poisoned. These packages had labels, such as "Danger: Contains Toxins", put on them. More tampered confections were found in February 1985, making a total of 21 lethal sweet products.
Unable to capture the suspect believed to be the mastermind behind the Monster with 21 Faces, the police superintendent Yamamoto of Shiga Prefecture committed suicide by self-immolation in August 1985. Five days after this event, on August 12, "the Monster” sent its final message to the media:
Yamamoto of Shiga Prefecture Police died. How stupid of him! We've got no friends or secret hiding place in Shiga. It's Yoshino or Shikata who should have died. What have they been doing for as long as one year and five months? Don't let bad guys like us get away with it. There are many more fools who want to copy us. No-career Yamamoto died like a man. So we decided to give our condolence. We decided to forget about torturing food-making companies. If anyone blackmails any of the food-making companies, it's not us but someone copying us. We are bad guys. That means we've got more to do other than bullying companies. It's fun to lead a bad man's life. Monster with 21 Faces.
After this letter, the Monster with 21 Faces was not heard from again. The statute of limitation for the kidnapping of Katsuhisa Ezaki, president of Glico, ran out in June 1995, and the statute of limitation for the attempted poisonings ran out in February 2000. No suspect was ever caught or convicted of the crimes, and the identity of the Monster with 21 Faces remains a mystery.
Following threats by the Monster with 21 Faces to poison Glico confections and the resulting mass withdrawal of Glico products from shelves, a man wearing a Yomiuri Giants baseball cap was caught placing Glico chocolate on a store shelf by a security camera. This man was believed to be behind the Monster with 21 Faces. The security camera photo was made public after this incident.
On June 28, 1984, two days after the Monster agreed to stop harassing Marudai Ham in exchange for 50 million yen, police came close to capturing the suspected mastermind. An investigator disguised himself as a Marudai employee and followed the Monster's instructions for the money exchange. As he was riding a train to the money's drop point, he noticed a suspicious man watching him. He was described as a large, well-built man wearing sunglasses and with his hair cut short and permed. He was also quoted to have "eyes like those of a fox." As investigators tailed him from train to train, the Fox-eyed Man (キツネ目の男, kitsune-me no otoko) eventually eluded them. In a later incident, investigators saw the Fox-eyed Man again, accompanying the alleged "Monster" group during another secret money exchange with House Food Corporation. Once again, he was able to elude police and avoid capture.
Tokyo Metropolitan Police at first identified Manabu Miyazaki, a known yakuza, as the Fox-eyed Man and the Videotaped Man because of his resemblance to these suspect, but after his alibis were checked, he was cleared of the Glico-Morinaga crimes.