The Case of the Attack on Shinji Miyadai — How the Suspect Went from Class Favorite to Middle-Aged Loner

It was revealed at the end of January that the man sought as a suspect in the incident in which sociologist Shinji Miyadai, 63, was slashed and seriously injured, had taken his own life. He had hanged himself just as the Metropolitan Police Department released security camera footage of the attack on December 12, 2022, in an effort to identify the culprit.

“The suspect believed to be responsible for this incident is Minoru Kuramitsu, 41, a resident of Sagamihara City, Kanagawa Prefecture. Four days after the release of the video, his mother found him hanging at another house about 300 meters from hers. The suicide note did not mention anything about the incident, but rather said that he had caused trouble for his family and acquaintances,” said a reporter from the society section of a national newspaper.

Kuramitsu lives with his father, who works as a plumber, and his mother, who works in the nursing care field. He had been living a reclusive life without work for many years. Kuramitsu, who cycled back and forth between his main residence and another house every day, was looked at strangely by neighbors.

He would go to his parents’ house at around 7:30 a.m. every day from a separate house that his mother had purchased for him, and return home around 9:00 p.m. at night. He always had a shaved head, wore a yellowed T-shirt, and rode a bicycle with his body rolled up. When I greeted him, he reacted as if he didn’t hear me, it was a little creepy.

The only known connection between Kuramitsu and Miyadai is a co-authored book found at his parents’ house. There are reports that his mother was a follower of the religion “Jehovah’s Witnesses,” but the motive for the murder has yet to be elucidated. However, our interviews have revealed how and when the suspect cut off contact with society and became a lonely, reclusive middle-aged man.

This magazine obtained Kuramitsu’s elementary and junior high school graduation albums and a collection of his writings. In elementary school, Kuramitsu was pictured with a cheerful expression on his face and was voted first in both “cool person” and “athletic person” in a class vote. His classmates in elementary and junior high school say that he was not the type of person who would withdraw from the class.

He was a quiet guy, but he was refreshingly good-looking and popular. He worked hard in junior high school on the baseball team. He never caused any trouble at school.

Kuramitsu wrote in his elementary school graduation album that his dream was to be a baseball player. However, his life seems to have taken a drastic turn for the worse after entering high school. An acquaintance who has known Kuramitsu since he was a child tells us, “The high school was a regular at the Koshien National High School Baseball Championships.”

I heard that he entered high school as a pitcher at a school that was a regular participant in the Koshien (the National High School Baseball Championship). It seems that the school had high expectations for him. …… He was always a very gentle boy, so he may not have been able to endure the rigorous training that kicked others out of school. He ended up dropping out of high school, and from there I hear he became a recluse.”

According to his mother, Kuramitsu did not even own a cell phone. This acquaintance continued, “After he dropped out of high school, he was never seen again.”

The mother said, “My son is mentally ill, and he’s at home all the time reading books. A few years ago, I saw him at the library, which is about a 20-minute bike ride away. He was reading so intently that he didn’t even notice me.”

Miyadai is known for his harsh criticism of people who embrace loneliness and live apathetically. In his solitary life devouring books alone, did the suspect Kuramitsu come into contact with Mr. Miyadai’s ideas and develop a one-sided resentment toward him? However, the opportunity to hear the true motive from his own mouth has been lost forever.

From the February 24, 2023 issue of FRIDAY