At the end of Kinji Fukasaku’s Gyangu tai G-men (US: Gang vs. G-Men), an entertaining thriller and textbook example of Japanese yakuza noir, one character asks another “What have we accomplished?” The question follows an explosive massacre that just turned a whiskey warehouse into the seventh circle of hell, so the answer is entirely unclear. The film’s ostensible hero is Ryoji Tojima (Kōji Tsuruta), a reformed yakuza member who’s persuaded by Detective Ogata (Yoshi Katō) to go undercover and collect evidence that will take down another yakuza gang run by Jūgo Tatsumura (Tetsurō Tamba), who conceals his illicit dealings behind a disguise of legitimate businesses. Pretending to have reentered the criminal underworld, Tojima collects a group of old friends and associates — a car thief, a gambler, a disgruntled cop, an extorted bartender — to begin canvassing Tatsumura’s small businesses, leading to an illegal smuggling racket and growing suspicion that Tojima isn’t who he says he is. All of the cast is exceptional, especially the supporting players who each bring a distinctive charm that adds comradery to the group and emotional resonance to the story. For viewers unexposed to yakuza films, this is a great place to start.