Anime Profile: Loveless

In this anime, people have cat ears, but they lose them when they lose their virginity (there is no hentai in it).

Ritsuka Aoyagi is a 12 year old boy who lives alone with his mother, Misaki Aoyagi. His brother, Aoyagi Seimei, was killed in an accident. Since even before Seimei's death, however, Ritsuka lost his memory and had a complete personality change, and his mother went insane saying he's not her son- that he doesn't look like him.

One day, Ritsuka meets somebody by the name of Soubi Agatsuma who claims to be a friend of Seimei. He knows the reason of his death and is ready to lend his help to Ritsuka. By searching for the cause of his brother's death (because Soubi can't tell him), Ritsuka will find much more than only that.

The story centers around a twelve year old boy named Aoyagi Ritsuka, who has a mysterious run-in with a man named Agatsuma Soubi on his first day of school. Soubi claims to have been close friends with Ritsuka's recently murdered brother Seimei. Soubi says that him and Seimei shared the true name of "Beloved" and were involved in magical spell battles. He also tells Ritsuka that he was the "Fighter" unit to "Beloved" and that Seimei was the "Sacrifice", and now that Seimei is dead Ritsuka is to be the "Sacrifice" for "Beloved".

In addition, Ritsuka is told that his own true name is "Loveless" and he is soon dragged into intense spell battles, which can be more or less described as magical chess matches. In these battles the "Fighter" uses word-spells to defeat the other pair of opponents and the "Sacrifice" takes all the damage of the attacks. Ritsuka is determined to figure out why his brother was murdered and concedes to the spell battles in order to find out what Soubi knows about the organization "Septimal Moon"; who Seimei blames for his death in a will that was left to Ritsuka.

As the story progresses more is revealed about Ritsuka, Seimei, Soubi, and the other characters involved in the spell battles.