AllMovie

Twelve-year-old Ritsuka Aoyagi lost his only family when his big brother Seimei died, and what's worse, the circumstances surrounding his death were quite mysterious. Things only get more mysterious, however, when Soubi shows up; he claims that he and Seimei were fighting partners, and while he was the "Fighting Machine," Seimei was the "Sacrifice." Now, the charming Soubi expects Ritsuka to take his brother's place. This may sound like a dangerous arrangement for a 12-year-old boy, but Ritsuka is determined to investigate his brother's death, and so he agrees.