In the wake of a third world war which left Japan in ruins, an organization known as Vischio seized control of Tokyo and renamed it Toshima. Taking place in its back alleys are battle games known as Igura, overseen by the Vischio, in which contestants battle and bathe in each other's blood to earn the chance to go up against its 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 the 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. [Written by MAL Rewrite]

Tightly clutching his Gibson guitar, Mafuyu Satou steps out of his dark apartment to begin another day of his high school life. While taking a nap in a quiet spot on the gymnasium staircase, he has a chance encounter with fellow student Ritsuka Uenoyama, who berates him for letting his guitar's strings rust and break. Noticing Uenoyama's knowledge of the instrument, Satou pleads for him to fix it and to teach him how to play. Uenoyama eventually agrees and invites him to sit in on a jam session with his two band mates: bassist Haruki Nakayama and drummer Akihiko Kaji. Satou's voice is strikingly beautiful, filling Uenoyama with the determination to make Satou the lead singer of the band. Though reticent at first, Satou takes the offer after an emotional meeting with an old friend. With the support of his new friends, Satou must not only learn how to play guitar, but also come to terms with the mysterious circumstances that led him to be its owner. [Written by MAL Rewrite]

In the world of Loveless, each person is born with cat ears and a tail, which disappear only if that person engages in a sexual intercourse. Because of this, they have come to symbolize virginity and innocence. Additionally, fighting is only done by "fighting pairs" or couples, where one is known as the Sacrifice and the other as the Fighter. The first receives the damage while the latter attacks. Ritsuka Aoyagi is a 12-year-old boy, who for some unknown reason suffers from amnesia. His brother got killed recently, and as if his life has not been hard enough lately, on his first day at the new school he gets approached by a stranger called Agatsuma Soubi, who claims to have known his late brother. Ritsuka finds out that Agatsuma and his brother used to be a fighting pair, and that Agatsuma has inherited Ritsuga now that his brother is gone. Together, they try to find the truth behind his brother's death and the organization known as the "Seven Moons," which may have been responsible for it. All the while, it seems that Ritsuka and Agatsuma are becoming closer than they intended to be…