Teppei Ono was a Japanese security guard who served as captain of Kubota Security, Takahiro Kubota's second-in-command, and as a member of the Nagoya-gumi. In 2012, he accused Ichiro Toriyama of breaking a valuable baseball bat in an attempt to extort him for money, but Tatsuo Shinada, the lover of Ichiro's sister Mieko Toriyama, arrived and revealed that the broken bat was a fake. Kubota then learned that Ono was taking on work from another company as well, and he retaliated by stabbing Ono in the cheek with a pen. Ono later confronted Shinada outside of work, blaming him for getting him stabbed. Shinada defeated Ono in another fistfight, forcing Ono to limp away in defeat.