Leo, a young, stoic boxer with a bleak outlook on life, unexpectedly discovers he has a terminal illness. His life takes a sudden turn when he crosses paths with Monica, a troubled young woman ensnared in the seedy world of drug trafficking and prostitution due to her father's debts. When a cunning yet desperate low-level Yakuza named Kase devises a risky plan to steal drugs and frame Monica for the theft, coincidences bring Leo and Monica together. Leo unintentionally becomes her protector after saving her from harm during a chaotic altercation involving corrupt cops and rival gang members.

As they navigate the dark underbelly of Tokyo, Leo and Monica grow closer, each finding a sense of purpose and connection that had eluded them before. While pursued by dangerous criminals including the vengeful Yakuza and paranoid conspirators, they fight to stay alive amidst growing chaos. Their journey through nocturnal streets becomes a whirlwind of incidents and alliances, leading both to confront their pasts and question their futures in a single night of relentless danger and fleeting hopes.