Aikawa, who is training hard for a crucial tournament that will determine his success as a martial artist; Toshiyuki, a former fighter now reduced to a shadow of his former self after running up a mountain of debt; Miki, who was deceived by her comrades and branded a traitor by her organisation; and Sawamura, a karateka burning with rage after witnessing his master being brutally murdered. One day, these four individuals—each burdened by their own circumstances—are forcibly brought together and compelled to participate in the ‘Basement Arena’, a fighting venue organised by a mysterious promoter. They are then ordered to fight fighters from every discipline. Determined to escape this place as quickly as possible, they throw themselves into an endless battle where ‘only the survivors will be set free’…