As a story, Knuckle Girl settles for the simplest beats, at times strung together by odd, obligatory choices (for example, a training montage that comes out of nowhere, or the film's abrupt ending). It's not particularly sophisticated as far as thriller narratives go. But taken as a showcase for boxing-centered action, the film really sets itself apart from many countless action movies on streaming. The fist-fights here are brutal and kinetic, shot through lots of dynamic footage and crunchy sound design—making every punch that's thrown feel desperate. And in the lead role, Ayaka Miyoshi makes for a convincing, everyman action star who always seems in over her head but perseveres all the same.

The fact that Ran is badly beaten to a pulp several times throughout Knuckle Girl makes all the difference. People tend to forget that some of the best action movies of all-time feature heroes who get hurt often and who practically crawl to the finish line through sheer strength of will. Ran follows in this tradition with her dignity intact; she remains incredibly capable and impressive as a fighter, but there's always a fear that she might sustain permanent injury during her fights. So even if Knuckle Girl might not be memorable as a story with distinct characters, Ran's face, coated in her own blood but still fighting tooth and nail, should be very difficult to forget.