Kiyo's father sends amnesic Zatch to live with him where he discovers that reading a spell from Zatch's book causes lightning to come out of Zatch's mouth. As the series progresses, Kiyo and Zatch befriend a Mamodo named
Kolulu who reveals that the Mamodo King forced her into the tournament. Zatch upon hearing her story strives to become the Mamodo King in order to bring peace to the Mamodo World. During the course of the story, Kiyo and Zatch befriend a super star named
Parco Folgore and his Mamodo
Kanchomé, an idol singer named
Megumi Oumi and her Mamodo partner
Tia, a Chinese girl named
Li-en and her Mamodo
Wonrei, a genius magician named
Dr. Riddles and his Mamodo
Kido, and later, a German man named
Kafk Sunbeam and his Mamodo
Ponygon. An evil Mamodo named
Zofis antagonists Kiyo and his friends prompting them to defeat him and prevent him from being the Mamodo King. After Zofis' defeat, a group of Mamodos plan to awaken the giant Mamodo
Faudo and use its power to win the Mamodo battles. Kiyo and his friends realize the threat Faudo could bring to the world and infiltrates Faudo's body in order to stop its resurrection. As they progress inside Faudo, Kiyo is killed in battle but is resuscitated into a catatonic state by Zatch. Zatch and friends move on and meet the one controlling Faudo,
Zeno who reveals he is Zatch's twin brother. Kiyo awakens and with Zatch battles and defeats Zeno and sends Faudo back to the Mamodo World. Later a powerful Mamodo named Clear Note reveals his intention to destroy the Mamodo world if crowned the Mamodo King. Kiyo and Zatch, with the help of friends, manage to defeat Clear Note leaving only Zatch and Brago battle as the remaining Mamodos. Zatch eventually engages and defeats Brago and is then crowned King of the Mamodo World. Zatch returns to the Mamodo world and restores the defeated Mamodos. Some time passes and Zatch sends Kiyo a letter telling him the peace of the Mamodo world. ==Appearances in other media==