Loveless - S01

In the world of Loveless, everyone is born with cat ears and a tail, which only disappear after a person has sexual intercourse. Because of this, they have come to represent virginity and innocence. On top of that, fighting is done only by "fighting pairs," or couples, in which one is the Sacrifice and the other is the Fighter. The first takes the damage while the second attacks. Ritsuka Aoyagi is a 12-year-old boy who, for reasons unknown, suffers from amnesia. His brother was killed recently, and as if his life has not been hard enough lately, on his first day at a new school he is approached by a stranger named Agatsuma Soubi, who claims to have known his late brother. Ritsuka learns that Agatsuma and his brother used to be a fighting pair, and that Agatsuma has inherited Ritsuka now that his brother is gone. Together, they try to uncover 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 growing closer than they intended to be...