Hoseki is a demon who wanders all over the Far East in search of a sword called Yoshimitsu, a katana handed down from generation to generation in a clan of bandidt ninjas, the Manji Clan. Since she was very young, other demons said to her that Yoshimitsu, with her Soul Edge fragment, which she has always had since she was created, she can generate a huge destroyer power. One day Hoseki met a devil with who made an agreement: she offers her soul to this devil trying to get hold of Soul Edge and in return she knows the secret to get hold of Yoshimitsu.