It starts as a sort of boxing love triangle drama, and ends as masochistic body horror, nearly abstract filmmaking, broken up by beautiful montages of the mechanical/utility layer of Tokyo and shots of brutalist architecture.
It reminded me of PORNOSTAR in its feverlike quality, and UNCUT GEMS in the way that it willingly forgoes cinema convention in exchange for an expression of uncomfortable mood. Also sorta reminded me of the manga FLOWERS OF EVIL (AKU NO HANA) in the way that both use a loose plot to explore pure human impulse, with no mastermind plan behind the viscera, just a dive into beasthood.