Loveless

Twelve-year-old Ritsuka Aoyagi is left with only his unstable mother after his brother Seimei dies unexpectedly. When he transfers to a new school, he meets Soubi Agatsuma, who says he knew Seimei. Ritsuka soon learns that Soubi and Seimei were once partners in battle-Seimei as the "Sacrifice" and Soubi as the "Fighter." With Seimei gone, Ritsuka inherits Soubi as his own Fighter. After discovering that the "Seven Moons" were responsible for his brother’s death, Ritsuka sets out to uncover the truth, with Soubi’s unreliable help along the way.