Ayashi no Ceres

It's the funeral-like atmosphere that tips off the twins: things are not what they seem at their birthday party. That, and the fact that their birthday present turns out to be a mummified hand. Soon Grandfather Mikage pronounces Aki the heir to the Mikage fortune, declaring that Aya must die. But Aya has allies in Yuhi, the athletic cook and martial artist, and in the attractive, mysterious Toya.