According to prefectural police, between 2012 and October of last year, Hiroaki Ono, the 51-year-old head of the Koyama-gumi, an affiliate gang of the Yamaguchi-gumi, allegedly threatened violence to operators of five restaurants in Wakayama City who do not pay protection money.
The demand is based on the Anti-Organized Crime Law, which prohibits extortion.
The headquarters of the Koyama-gumi is located in Wakayama City.
