Sensei Billy

Sensei Billy is a Gōjū-ryū karate instructor in Scranton, portrayed by Michael Imperioli.

Overview
In the season 9 episode "Livin' the Dream", Dwight holds his black belt ceremony at the office, with Sensei Billy watching. It is clear that Billy is much more laid back than Dwight's previous sensei, Sensei Ira, because he lets others simply call him by his first name. According to Billy, "most students don’t spend $150,000 over 20 years to get their black belt". Billy finds Dwight annoying but highly tenacious and determined, with a similar opinion as Dunder Mifflin CEO David Wallace, who attends the ceremony along with the rest of Dwight's coworkers. Billy's recommendation and appraisal of Dwight's skills helps to convince David to promote him to the position of Regional Manager.