Subordinate Gang Leader Arrested Over Last Year’s Assault Incident Involving Two Men

“I will arrest them for even the smallest things.”

A man walking down the stairs of a police station building. Noticing the press holding cameras, he exchanged a few words with the accompanying police officer with a suspicious expression. Then he faced forward again and fixed his gaze squarely on the reporters.

On April 16, the man arrested on suspicion of assault at the Nerima Police Station in Tokyo was Yonamine Masatoshi, 50, the leader of the Yonamine Group under the Sumiyoshi-kai Kōhei Ichikawa faction. He was sent to prosecutors on the morning of the 17th.

“Yonamine is suspected of assaulting two men on a street in Nerima Ward, Tokyo, last year by throwing them to the ground. According to police, a dispute over payment had occurred at a snack bar involving one of his acquaintances, and Yonamine, who was nearby, rushed to the scene and assaulted the owner of the bar and a male employee,” said a reporter from a national newspaper’s social affairs desk.

The Kōhei Ichikawa faction is believed to have close ties with tokuryū (anonymous, fluid-type criminal groups) involved in special fraud and “dark part-time job” robberies, and is also thought to be connected to “Natural,” one of the largest illegal sex industry recruitment groups in Japan. In addition, it is believed to be involved not only in methamphetamine trafficking but also in the distribution of so-called “zombie tobacco,” which has spread among young people in Okinawa, generating massive profits. It is now said to be one of the largest criminal organizations in Tokyo.

In January this year, the Tokyo Metropolitan Police Department established a special task force targeting the Sumiyoshi-kai Kōhei Ichikawa faction under the direction of the Criminal Affairs Bureau Director. At a press conference at the time, Toshihiko Ōba, a superintendent in the Organized Crime Control Division of the Tokyo police, stated:

“We will arrest any crime connected to the Kōhei Ichikawa faction.”

True to those words, investigations are now being carried out thoroughly, even revisiting past unsolved cases believed to be linked to the faction.

In March, five members of an affiliated group were arrested on suspicion of confinement and robbery resulting in injury. On April 2, another member was arrested on suspicion of extortion. Furthermore, on April 13, a group member was arrested for allegedly importing 5 kg of methamphetamine (street value approximately 268 million yen) in 2024. The current assault case also dates back at least four months. Crime journalist Yasuhira Ogawa commented:

“This is clearly part of a concentrated crackdown on the Kōhei Ichikawa faction. The police are demonstrating a strong stance. For example, around 2009, the Aichi Prefectural Police established a special investigation unit targeting the Yamaguchi-gumi Kodokai. The Metropolitan Police are now similarly focusing heavily on the Kōhei Ichikawa faction.

In the past, even if there was a complaint, minor disputes between associates that would not lead to prosecution might not have been treated as cases. But now, they are actively taking people into custody for any available information involving assault. The criteria are no longer based on whether prosecution is likely. Since the arrested individual here is a gang leader under the faction, it has significant value for the police as a show of force—no matter how small the case, whether low-level or leadership, we will arrest anyone connected to the Kōhei Ichikawa faction.”

During questioning, Yonamine denied the charges, stating: “I was only trying to mediate a fight.”

Yonamine Masatoshi denies the charges, stating that he only stepped in to mediate the situation.