Police have accused Yoshiaki Baba, the 36-year-old former leader of Dragon, of possessing two pistols and ammunition in June.
According to police, Baba, who is a also a former member of the Sumiyoshi-kai organized crime group, passed an attache case containing the contraband to another man who is already in custody. The man then hid the case in a park in Edogawa Ward.
The core membership of Dragon is comprised of second- and third-generation returnees from China who came to Japan after the end of World War II.
Law enforcement had long viewed Dragon as a bosozoku motorcycle gang. However, starting in 2013 the National Police Agency began classifying bosozoku gangs as “pseudo-yakuza” groups to better reflect the true state of their activities.
Police are now investigating where Baba obtained the weapons and ammunition.