Following a third world war that left Japan in ruins, an organization called Vischio took control of Tokyo and renamed it Toshima. In its back alleys, battle games known as Igura take place under Vischio's supervision, where contestants fight and bathe in each other's blood to earn the chance to face the tournament's king, Il-re. Igura is not the only fighting tournament around; Bl@ster is a similar yet vastly different game since it prohibits murder and the use of weapons. The only way to win is by knocking out the opponent. Akira, a young man isolated from his family, is known to be undefeatable at Bl@ster. However, his life on top is shattered when he is accused of murder. Unable to prove his own innocence, all hope is seemingly lost... that is until a mysterious woman named Emma appears and offers him a chance. Now, to regain his freedom, Akira must participate in Igura and ultimately defeat Il-re.