Akane and her parents were shot dead as foxes by a human hunter in the past. In Episode 10 of "Tenshi no Shippo Chu!" Akane's mother returned to earth as a vengeful spirit. She has hatred for humans. For her, they are "intolerable" and because of this, she wants to become a nine-tailed fox, hoping to drop humans into a pit of fear. She tried to convince her daughter Akane to leave the humans' world with her and help her become a nine-tailed fox, but her daughter refused. Akane told her mother that not all humans are bad, especially her master Goro. Realizing that Akane loves Goro very much, the mother allowed her daughter to stay on earth. In the end, Akane's mother left the humans' world alone. Before leaving the earth, she told Akane that she will restore her hunting instincts if something makes her daughter cry. She also promised that she will come back again to earth.
Yomi's advisor, Yoda is a technological genius, creating various devices, such as the energy meter that tells an opponent's youki level in numbers. During the Makai Tournament, he assists Koto as announcer.
Darth Vader is the central antagonist in George Lucas' original Star Wars trilogy and his final prequel, Star Wars Episode III: Revenge of the Sith. In the original trilogy, George Lucas depicts Darth Vader as a fearsome cyborg who acts as the supreme commander of the brutal Galactic Empire. Throughout the films, Vader oppresses the galaxy and hunts down the members of the Rebel Alliance in the service of his master, Emperor Palpatine. the series' final chronological installment, Vader redeems himself by killing Palpatine and saving his son Luke, sacrificing himself in the process. Lucas shows Vader as his former self, Anakin Skywalker, a slave boy who eventually becomes a Jedi Knight, and later, a hero in the Clone Wars. Palpatine manipulates Anakin into betraying the Jedi, and Anakin falls to the "dark side" of the mystical Force.