Hyde (ハイド, Haido) and Eido (窪塚泳太, Kubozuka Eita) are the very first mamodo team that Zatch and Kiyo encounter in the anime, that had to leave the battle when Kiyo cast Zaker for the first time. Their powers are related to wind. Hyde is a serious mamodo who wants to become king of the mamodo world. Hyde finds Eido being picked on by bullies and offers him his powers to be strong. Eido is an air-headed partner of Hyde who loves to skateboard, eat yellowtail hamburgers, he's crazy with girls, and he loves Megumi and her music. Hyde describes him as the opposite of Kiyo; he doesn't go to school, have any friends, and is a poser. He also isn't very smart, as when he left a note for Kiyo to come save his friends, he didn't mention where to go.
At first, Eido seems to only care about using Hyde's power to steal things unseen. He also uses the power to peek at girls' panties, which irritates Hyde to no end. They meet Zatch and Kiyo on the rooftop of Mochinoki's high school after Eido decides that Suzy will be his girlfriend, but they are easily defeated when Kiyo figures out how to use the spellbook to protect Suzy.
They return and force a rematch by kidnapping Kiyo's friends. When Kiyo and Zatch come, Eido and Hyde overpower them with constant attacks while flying in the air while Zatch and Kiyo are saving their friends. Kiyo was able to outsmart them and Zatch aims to Eido's book to finish the battle when Hyde jumps on the way to protect him. At that time, Eido wants to retreat but Hyde goes to fight Zatch on his own, tired of Eido's cowardice. When Hyde is about to be attacked by a spell, Eido protects Hyde by taking the spell himself. He says that Hyde might be able to give him strength and Hyde replies he is already strong when he protected him. With that, a new spell appears in the book, Jikirga. They use it against Zatch's Rashield and the two spells cause a large explosion, causing a draw between the two teams. They managed to escape at the last second without getting their book burned.
Hyde and Eido were last seen at a Megumi Oumi concert during her first appearance on the series and never again; but as he does not advance to the King's Festival it can be inferred that his book was burned sometime between then and the King's Festival.
Though none of the above events occur in the manga, Hyde is seen among the mamodo assisting Zatch with his final attack on Clear Note during the King's Festival. In the mamodo world, Hyde is also shown at school talking with Pamoon.