Tokyo Fist
Where to watch in US
Not currently streaming in US.
A businessman, Tsuda, runs into a childhood friend, Kojima, on the subway. Kojima is working as a semiprofessional boxer. Tsuda soon begins to suspect that Kojima might be having an affair with his fiancée Hizuru. After an altercation, Tsuda begins training rigorously himself, leading to an extremely bloody, violent confrontation.